Classifications

• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06N—COMPUTING ARRANGEMENTS BASED ON SPECIFIC COMPUTATIONAL MODELS
  • G06N10/00—Quantum computing, i.e. information processing based on quantum-mechanical phenomena
  • G06N10/20—Models of quantum computing, e.g. quantum circuits or universal quantum computers
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21G—CONVERSION OF CHEMICAL ELEMENTS; RADIOACTIVE SOURCES
  • G21G1/00—Arrangements for converting chemical elements by electromagnetic radiation, corpuscular radiation or particle bombardment, e.g. producing radioactive isotopes
  • G21G1/0005—Isotope delivery systems
• • G—PHYSICS
  • G16—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR SPECIFIC APPLICATION FIELDS
  • G16C—COMPUTATIONAL CHEMISTRY; CHEMOINFORMATICS; COMPUTATIONAL MATERIALS SCIENCE
  • G16C10/00—Computational theoretical chemistry, i.e. ICT specially adapted for theoretical aspects of quantum chemistry, molecular mechanics, molecular dynamics or the like
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21B—FUSION REACTORS
  • G21B3/00—Low temperature nuclear fusion reactors, e.g. alleged cold fusion reactors

Definitions

• the present invention relates to a system and method for optimizing energy transfer and conversion in quantum systems and in particular to a system and method for optimizing energy transfer and conversion in quantum systems by using quantum simulations.
• Quantum systems such as atoms, molecules, nuclei
• Excited states are characterized by the amount of energy held by the quantum system in the respective state (compared to the ground state) and by the lifetime of the state.
• a quantum system When a quantum system is in an excited state, it can become de-excited by turning to lower excited states or to an unexcited state of the quantum system. In the course of the de-excitation, energy of an amount corresponding to the difference between the original state and the resulting state transfers out of the quantum system.
• the lifetime of a state can range from less than nanoseconds to more than millions of years.
• an optimal implementation of a technology for a particular use case is referred to as the dominant design.
• Dominant designs can emerge in an evolutionary manner through trial and error or, alternatively, through systematic optimization, typically based on simulations of the behavior of the considered device system and its variants. Through the latter approach, the arrival at a dominant design - and subsequent large-scale dissemination of the technology in question - can be greatly accelerated. What is necessary to that end is a method for systematic optimization of the design - and a slightly different one for each use case - which in turn depends on having identified causal relationships between input variables and output variables (i.e. the system outcomes to be optimized).
• the preferred materials composition evolved from Ge crystals with Sb doping at a concentration of around 10 15 cm' 3 , as predominantly used in the 1940s, to Si crystals with B doping used by the late 1950s. If systematic modeling tools that captured the essential causal relationships governing transistor function had already existed during the late 1940s, then the effect of different input parameters (such as materials composition) on output variables of interest could have been determined more systematically. As a result, dominant designs for transistors for various use cases would have arrived earlier and dissemination would have occurred faster. This example illustrates how the ability to systematically predict, compare, and optimize the design implementations of new technologies are critical for large-scale dissemination and for the effective use and deployment of emerging technologies.
• the invention relates to the design of energy transfer and conversion in quantum systems, and more specifically, to the use of quantum simulations and related modeling techniques to predict the quantum dynamical behavior of alternative system designs, to compare their performance, and to select the most desirable of such alternative designs.
• Alternative variants of device systems thus compared, differ based on direct, controllable input variables such as materials composition, environmental conditions, and stimulation characteristics, as well as indirect variables that follow from the direct variables such as the structure, mechanical, and optical behaviors of the materials that result from design choices.
• Subsequent comparison and evaluation of alternative variants of systems take place based on the ability to achieve desired outcomes according to pre-defined criteria.
• Such criteria can include, but are not limited to, a minimum rate of charge production, nontoxicity of materials, longevity of the device system, and materials within a certain price range.
• the invention features a computer implemented method for optimizing energy transfer and conversion in coupled quantum systems, and for creating corresponding device designs.
• the method includes the following steps. First, providing a database comprising input variables of one or more quantum systems in a lattice sample of a single material or an alloy or a composite material. Next, modeling an initial crystal structure of the lattice sample at a first set of environmental parameters via a computing engine. Next, adding a dopant to the lattice sample and determining a new equilibrium state of the lattice sample at a second set of environmental parameters via the computing engine. This step is repeated if more than one dopant is added.
• determining lattice-related oscillator characteristics such as phonon-modes and photon absorption in the new equilibrium state of the lattice sample via the computing engine Next, estimating state transition rates for a first quantum system in the lattice sample in the absence of any strong coupling to a second quantum system via the computing engine. Next, determining presence of any coupling and coupling strength of the first quantum system to the second quantum system via the computing engine. Next, providing coherent stimulation of the lattice sample via the computing engine, thereby populating oscillator modes that the first quantum system and the second quantum system both participate in. Next, determining presence of coupling and enhancement of coupling strength of the first quantum system to the second quantum system after the coherent stimulation of the lattice sample via the computing engine.
• the direct and indirect input variables include compositions and structure of the single material or alloy or composite material of the lattice sample, energy levels, state lifetimes, and multipolarity of the quantum systems in the lattice sample, geometric arrangements of the quantum systems in the lattice sample, lattice- related oscillator characteristics, and characteristics of the coherent stimulation of the quantum systems in the lattice sample.
• the coherent stimulation is carried out by laser irradiation of the sample lattice and the characteristic of the coherent stimulation comprise a laser wavelength p , pulse energy E p , pulse length t p , repetition rate r p , and spot size A p .
• Each set of environmental parameters comprises a temperature, a pressure, an equilibrium time, and optionally an applied electromagnetic field.
• the method may further include modelling formation and diffusion of dopant-stabilized vacancies in the new equilibrium state of the lattice sample at a third set of environmental parameters via the computing engine, after the addition of the dopant to the lattice sample.
• the output variables include form of energy (kinetic or potential), and amount of energy released from the lattice sample as result of the coherent stimulation applied to the lattice sample, overall energy balance AE (energy released from the sample divided by energy applied to the sample), and list of reaction products and particles.
• the method may further include substituting the dopant with a different dopant or adding a different dopant and reiterating the above-mentioned steps via the computing engine.
• the quantum systems comprise one or more of nuclei, atoms, ions, and molecules.
• the equilibrium state of the lattice sample and phase stabilities are calculated with a density functional theory (DFT)-based method.
• the DFT-based method includes all of its variants, and all of its equivalents known by different names, as well as all the semi-empirical methods where some parts of the total energy function are approximated and some parts are simulated, such as, Quantum Espresso software package, Atomic Simulation Environment (ASE) software packages, VASP with Phonopy software packages, or an open-source stochastic self-consistent harmonic approximation (SSCHA) software package.
• the method may further include calculating background electron density in the vicinity of the dopant via the DFT-based method.
• the method may further include estimating background electron density in the vicinity of the dopant based on experimental and theoretical values given in the literature.
• the energy transfer can be accompanied by forms of energy conversion such as upconversion and downconversion if there is a suitable configuration of donor systems and acceptor systems (also referred to as receiver systems) that enable such dynamics.
• the invention features a non-transitory computer-readable storage medium containing a computer program for optimizing energy transfer and conversion in quantum systems, and for creating corresponding device designs.
• the computer program when executed by a computing processor includes:
• FIG. 1 illustrates schematically a process of de-exciting quantum system A while exciting quantum system B through a temporarily enhanced coupling between A and B (flipping two qubits A and B from states 11> and
• FIG. 2 illustrates schematically the process of accelerating the nuclear quantum state transition from the 14 keV
• FIG. 3 illustrates schematically the process of accelerating the nuclear quantum state transition from the
• FIG. 4A illustrates schematically the process of accelerating the nuclear quantum state transition from the
• FIG. 4B depicts data obtained from an experimental configuration with a D-implanted Ti and U sample, testing the quantum dynamics represented in FIG. 4A, which resulted in 28 MeV charged particle detection;
• FIG. 5 depicts an overview diagram of the system for modelling energy transfer in coupled quantum systems, according to this invention.
• FIG. 5A is a schematic diagram of the process for modelling energy transfer in coupled quantum systems, according to this invention.
• FIG. 5B depicts an exemplary apparatus for generating and monitoring energetic particle emission via phonon-mediated nuclear excitation transfer
• FIG. 6A is a flow diagram of the process for modelling energy transfer in coupled quantum systems, according to this invention.
• FIG. 6B is a detailed flow diagram of step A of the process of FIG. 6A;
• FIG. 7 depicts an example of phonon mode prediction for a Si lattice in a plot of density of states versus frequency from Density Functional Theory (DFT)-based lattice simulation techniques (Phonopy and VASP) along with the input parameters used;
• DFT Density Functional Theory
• FIG. 8A depicts an example of nuclear excited states of isotopes Li-6 and He-4 as obtained from NuDat data via a Python wrapper library
• FIG. 8B depicts an example of nuclear states as predicted by NuShellX code and are to be considered in step F of the process of FIG. 6 A;
• FIG. 8C depicts the table of nuclides, which represents the full repertoire of building blocks that the designer can draw on in considering lattice compositions in step F of the process of FIG. 6 A.
• FIG. 9 depicts schematically a power production device to be designed and optimized according to this invention.
• FIG. 10 A, FIG. 10B, and FIG. 10C depict schematically the energy transfer process in the embodiment of FIG. 9;
• FIG. 11 depicts schematically spontaneous emission in an uncoupled lossy oscillator simulated according to the method of this invention
• FIG. 12 depicts schematically energy transfer between two coupled lossy oscillators simulated according to the method of this invention
• FIG. 13 depicts schematically temporary increase of coupling strength between two coupled lossy oscillators simulated according to the method of this invention
• FIG. 14 depicts schematically upconversion resulting from increase of coupling strength between three coupled lossy oscillators simulated according to the method of this invention
• FIG. 15 depicts schematically downconversion resulting from increase of coupling strength between three coupled lossy oscillators simulated according to the method of this invention
• FIG. 16 depicts an experimental set-up for observing the simulated energy transfer processes according to this invention
• FIG. 17 depicts an exemplary computing system for the implementation of the computer code 415 of the present invention.
• the present invention relates to the design of devices that involve energy transfer and conversion in quantum systems, and more specifically, to the use of quantum simulations and related modeling techniques to predict the quantum dynamical behavior of alternative system designs, to compare their performance, and to select the most desirable of such alternative designs.
• Alternative variants of systems thus compared differ based on direct, controllable input variables such as materials composition, environmental conditions (also referred to as boundary conditions), and stimulation characteristics, as well as indirect variables that follow from the direct variables such as the structure, mechanical, and optical behaviors of the materials that result from design choices.
• Subsequent comparison and evaluation of alternative variants of systems take place based on the ability to achieve desired outcomes according to pre-defined criteria.
• Such criteria can include, but are not limited to, a minimum rate of charge production, nontoxicity of materials, longevity of the device, and materials within a certain procurement price range.
• Quantum systems are any physical systems at the nanometer and sub-nanometer scale that can absorb and release energy in a quantized manner (and thus can exhibit excited states and ground states, referred to as ‘states’). This includes, but is not limited to, atoms, molecules, and nuclei. Multiple quantum systems can be coupled through physical interactions that couple (some of) their states and can thus form larger, coupled quantum systems comprised of individual quantum systems. Such larger, coupled quantum systems are here referred to as ‘coupled quantum systems’ or ‘compound quantum systems’. Note that many coupled quantum systems are also quantum systems.
• individual quantum systems and coupled quantum systems can be part of a larger lattice which is here referred to as a ‘sample lattice’ or ‘sample’.
• the lattice does not necessarily have to be regular but can also be amorphous.
• Sample lattices can be part of larger systems that can be seen as devices whereas such devices can comprise multiple components that interact in a specific manner to achieve a specific purpose, per the device design.
• Such overall systems are here referred to as ‘device systems’, or simply ‘devices’.
• Couplings between quantum systems can be direct or indirect. In the case of direct couplings, physical dynamics in one quantum system directly impact physical dynamics in another quantum system.
• oscillators and ‘oscillator modes’ describe any oscillators and their modes that can cause an indirect coupling between the states of at least two quantum systems in the device.
• Such oscillators can take the form of coherent photons, phonons, or plasmons, among others, each of which exhibits physical mechanisms of interacting with quantum systems such as atoms and nuclei through basic principles e.g. electromagnetic and mechanical/relativistic principles, as has been studied in detail for each combination of major types of oscillators and major types of quantum systems.
• the corresponding literature that studies such basic interactions also describes the determination and estimation of coupling strengths between quantum systems under given circumstances i.e. in the presence of different oscillators that are shared across quantum systems.
• the key issue of interest is typically whether the couplings between the states of different quantum systems - and especially after all possible enhancements have been taken into account — are strong enough to result in modified dynamics (compared to weak or unenhanced couplings) with observable outcomes.
• the optimization and design principles described here apply across devices whose operations are based on different types of couplings and resulting energy transfer between quantum systems.
• Quantum systems such as atoms, molecules, nuclei
• Excited states are characterized by the amount of energy held by the quantum system in the respective state (compared to the ground state), by the lifetime of the state, and in some cases by other aspects such as the multipolarity of the state.
• lifetimes can range from less than nanoseconds to more than millions of years.
• lifetimes of states are not fixed values but exhibit some randomness according to probability distributions whose means are referred to as half-lives of the respective states. Such half-lives correspond to (by inverse proportionality) mean state transition rates which are here simply referred to as state transition rates or transition rates.
• the state transition rate corresponds to the reaction rate (e.g. alpha particle emission from an excited nucleus can be equally seen as a state transition and as a nuclear reaction, depending on the viewpoint and preferred nomenclature).
• the probabilistic distribution of observed de-excitation times of a quantum system A is impacted by the number and the strengths of couplings from the state of that quantum system A to states of other quantum systems which can - individually or collectively - accommodate the energy of said quantum system A.
• the so-called Fermi’s Golden Rule applies, and de-excitation times follow an exponentially shaped probability distribution.
• de-excitation follows a nonexponential probability distribution such as a sinusoidal distribution where state occupation probabilities oscillate back and forth between the two strongly coupled quantum systems (known as Rabi oscillations). It follows that de-excitation times can be affected by changing the strengths of couplings between quantum systems of interest. This effect is employed in quantum computing applications where “flipping a qubit”, i.e. switching a qubit from
• qubits A and B are initially in state where A is
• the increase in coupling strength leads to a transfer of excitation from quantum system A to quantum system B.
• a qubit is a quantum system per the above definition and can be physically implemented in a variety of ways, whereas the principles and methods described here are independent of the specific physical implementation.
• quantum computing applications the focus lies on the information content of quantum systems (qubits)
• energy applications the focus lies on the amount of energy (as measured in eV) held by quantum systems.
• Energy associated with quantum systems can take different forms, specifically: potential energy and kinetic energy.
• the de-excitation of a quantum system from an excited state to a lower excited state, or to the ground state corresponds to a conversion of energy from potential energy to kinetic energy.
• Potential energy in one modality represents the energy attributed to electrons whose constellation forms the excited state of an atom or molecule.
• potential energy represents the binding energy attributed to the nucleons whose constellation forms the excited state of a nucleus.
• kinetic energy describes the energy of a moving quantum system such as an emitted photon or other particles to which released potential energy gets transferred.
• Different energy levels of a quantum system i.e. excited states and the ground state, can be thought of as different energetic configurations of components of that system, e.g. the configuration of electrons in atomic level quantum systems and the configuration of nucleons in nuclear level quantum systems.
• a state transition of a quantum system e.g. from a higher energetic state to a lower energetic state, can then be thought of as a rearrangement of electrons, or nucleons respectively, from one configuration to another configuration.
• certain nanoscale dynamics that are sometimes referred to as ‘reactions’ de facto fall under the more general umbrella term ‘state transitions’. Consequently, the above considerations apply to them.
• Coupled quantum systems such as a solid-state lattice which includes multiple individual quantum systems such as atoms, molecules, or nuclei
• couplings between them, and corresponding energy transfer pathways will be those with the fastest time constants i.e. the fastest transfer and transition rates.
• a critical point is that in coupled quantum systems the mediating oscillators that provide coupling, or enhance coupling, do not need to be able to carry the same amount of energy as the energy that is transmitted between quantum systems as a result of their mediation. This is a critical difference between nonradiative energy transfer, as described here, and radiative energy transfer. In the latter case, an oscillator that couples to an excited state needs to be able to carry the entire quantum of the state transition energy of the quantum system. In other words, in the case of nonradiative energy transfer, as described here, the coupling, as expressed in eV, can be much weaker than the affected state transitions, as expressed in eV.
• this new domain can be referred to as nuclear quantum engineering, or as quantum-coherent nuclear engineering.
• nuclear quantum engineering or as quantum-coherent nuclear engineering.
• the implication is more degrees of freedom in the exploitation of nuclear reactions and the design of corresponding systems. Effectively, this means that well-chosen arrangements of nuclei (and the potential nuclear reactions that they can undergo) can be instigated and triggered by the provision of the right kind of couplings, or coupling enhancements, between the participating quantum systems (e.g. via coherent phonons) i.e. couplings and coupling enhancements that lead to desired outcomes.
• This invention describes methods and systems for designing and optimizing such systems based on modeling and simulating their behavior, and specifically the dominant energy transfer pathways and corresponding reaction rates and reaction products in different variants of such systems, through integrated modeling of nuclear level and atomic level features.
• Another example pertains to a state transition of a quantum system that is traditionally viewed as a nuclear reaction.
• a quantum system that is traditionally viewed as a nuclear reaction.
• FIG. 3 The excitation of a compact four-nucleon-configuration
• He-4> quantum system is thus resonant with the
• He-4> state transition is about
• the U-238* nucleus disintegrates incoherently via particle emission such as alpha emission (fast He-4 nucleus with about 28 MeV of kinetic energy, as can be determined from the corresponding mass defect) and the initially coherently transferred energy from the donor quantum system to the acceptor quantum system is thus eventually carried away incoherently in the form of kinetic energy.
• particle emission such as alpha emission (fast He-4 nucleus with about 28 MeV of kinetic energy, as can be determined from the corresponding mass defect) and the initially coherently transferred energy from the donor quantum system to the acceptor quantum system is thus eventually carried away incoherently in the form of kinetic energy.
• the incoherent energetic particle emission can be precluded if sufficiently strong couplings exist that make further coherent excitation transfer to another receiver system faster than the otherwise incoherent disintegration. In that case, the fastest pathways affecting the following receiver system need to be considered to predict overall observables, and so on.
• D2> quantum system transitions to its
• This de-excitation state transition, and the corresponding excitation state transition occur at a rate larger than the 10' 64 /s of the uncoupled spontaneous
• the excited U-238 nucleus subsequently decays via emission of an energetic He-4 nucleus i.e. an alpha particle.
• the process involves a potential-to-potential-to- kinetic energy conversion.
• FIG. 4B Experimental data exhibiting the observed 28 MeV charged particles in the abovedescribed configuration is shown in FIG. 4B where the x-axis represents charged particle energy in MeV and the y-axis the number of particles detected by the charged particles detector at each energy bin. Data shown was obtained via the experimental apparatus depicted in FIG. 5B with a sample material of Ti with added U at a U:Ti ratio of at least 1 : 10 A 7. The corresponding energy level diagram is shown in FIG. 4A, depicting the nonradiative energy transfer of 24 MeV followed by the incoherent decay of the U-238 acceptor nucleus in its highly excited state via 28 MeV alpha particle emission (which then becomes detectable).
• the method described here in one aspect describes a computer implemented method for an accelerated path toward dominant design development for various use cases of energy transfer and conversion systems with coherently enhanced state transitions.
• the energy transfer system input variables and output variables
• This invention also describes a computer implemented optimization method, process, and implemented code for the design of systems in which quantum state transitions and thus energy transfer and energy conversion dynamics between coupled quantum systems are coherently enhanced.
• the invention allows designers of devices to determine the optimal choice of input variable values for reaching the parameter subspace of desired output variable values in the overall parameter space that results from relating input variables to output variables.
• Such an approach - as described in this invention is also known as a ‘rational engineering’ approach. More specifically, as described here, the approach can be referred to as ‘resonance engineering’, as it is concerned with the exploitation of resonances or near-resonances between quantum systems that are coupled, through the deliberate arrangement and stimulation of such quantum systems. The term is applicable both to resonances between atomic and between nuclear states of different quantum systems.
• a system 100 for optimizing energy transfer and conversion in quantum systems by using quantum simulations includes databases 485 that contain input variables 160, a modeling engine 480, and storage 488 that contains the calculated output variables 170.
• the modeling engine 480 includes at least one computing device 400 or a computing architecture of networked devices and a computer code 415 that contains computer implemented instructions for optimizing energy transfer and conversion in quantum systems by using quantum simulations.
• FIG. 5 A exhibits the major physical magnitudes and relationships to be considered in the case of atomic nuclei as quantum systems coupled via shared coherent phonon modes.
• the computer code 415 receives inputs 160 about the atomic lattice structures 110 of lattices of one or multiple species of atoms, and about the couplings 120 between atomic or nuclear states 130 of at least two such atoms based on methods of coupling the energetic states of nearby quantum systems such as atoms or nuclei.
• Atomic lattice structures 110 are lattice structures composed of nuclei M that have a distance d between the reactants and phonon modes at frequencies o [as represented in the form of a vector/array].
• Inputs 160 to such a code are compositions and structure of the single material or alloy or composite material of the lattice sample, the energy levels, state lifetimes, and the multipolarity of the quantum systems in the sample (e.g. of the nuclei); the dominant decay channels of relevant excited states of quantum systems in the sample (e.g. of the nuclei); the geometric arrangement of the quantum systems in the sample including the proximities between quantum systems in the sample as well as related effects such as electron screening corresponding to the free electron density in the lattice (whereas the geometric arrangement and free electron density are determined by the atoms’ atomic properties and environmental conditions imposed); and the characteristics of stimulation such as the frequency and flux of coherent photons or phonons which in turn depend on the stimulation mechanism, e.g.
• Outputs 170 to such a code are then the transition rates of the state transitions of interest in the sample as well as the final products that result from the dynamics of dominant transitions (after short-lived intermediate states have been traversed).
• Constraints on the overall optimization process imposed by the designer can include such aspects as the desired final products of the system (e.g. only charged particles in a particular energy range), the range of input materials (e.g. only materials within a certain procurement price range or excluding materials with high toxicity), and overall device characteristics (e.g. energy and power density of the device).
• an exemplary apparatus 500 for generating and monitoring energetic particle emission via phonon-mediated nuclear excitation transfer includes a sample assembly 510, a particle detector 502 and a H and D ion beam 505 generated by an ion source 504.
• Sample assembly 510 includes a vacuum chamber 506 and sample 508 supported on a sample holder 507 within the vacuum chamber 506.
• phonon-mediated nuclear excitation transfer leads to a change of nuclear reaction products (from a first nuclear reaction [energetic particles with a first energy] to reaction products of a second nuclear reaction/disintegration [energetic particles with a second energy]).
• FIG. 5A is exemplary. Other embodiments of the system may utilize different sets and arrangements of atomic level and nuclear level data, variables, and calculations to the same end of optimizing energy transfer and conversion in quantum systems.
• the embodiment illustrated in FIG. 5A should therefore not be interpreted to be exclusive or limiting, but rather exemplary or illustrative. Integrated atomic and nuclear codes with optimization function
• the present invention describes the integration of multiple distinct techniques and codes to represent and simulate the behavior of coupled quantum systems, as described above, and allow for both manual and automated optimization of selected outcome parameters as a function of input parameters, and the corresponding design of high- performing devices.
• At the core of this invention in one aspect lies the combination and integration of atomic level modeling techniques and data with nuclear level modeling techniques and data, in order to optimize the performance of the above described device systems and, specifically, the dynamics of their constituent coupled quantum systems.
• Such coupled quantum systems extend over areas across at least several Angstroms and, in some cases, many nanometers.
• the description below focuses on an application of the method according to this invention that uses nuclei as the quantum systems whose dynamics are to be affected. Analogous principles apply when working with atomic level quantum systems.
• Step A Determine intermediate variables “equilibrium proximities of nuclei”, “electron screening potentials”, “oscillator characteristics” (which, depending on the shared oscillators used, can be “phonon modes”, and “photon absorption”) of the sample lattice from input variables “composition”, “environmental conditions”, and “equilibration time” (201).
• the intermediate variables are determined using a Density Functional Theory (DFT)-based method (which includes all of its variants, and all of its equivalents known by different names, as well as all the semi-empirical methods where some parts of the total energy function are approximated and some parts are simulated) such as Quantum Espresso software package, Atomic Simulation Environment (ASE) software package, or an open-source stochastic self-consi stent harmonic approximation (SSCHA) software package.
• DFT Density Functional Theory
• ASE Atomic Simulation Environment
• SSCHA stochastic self-consi stent harmonic approximation
• FIG. 7 Shown in FIG. 7 is an example for the density of states of phonon modes with frequencies o from a simulated lattice based on DFT calculations.
• Step A optionally includes the following sub-steps Al -A3.
• Step Al Model initial crystal structure and interstitial site occupation (211).
• dopants such as hydrogen isotopes are added through pressure or electrolysis and the new equilibrium condition is determined at temperature T2 and pressure p2 as of equilibrium time t eq 2.
• Recommended starting materials include, but are not limited to, Pd, Ni, Li, Ti, Ta, W, Mg, Pb, Fe.
• dopant describes the addition of a material to a lattice at low or high concentrations, including very high concentrations on the order of, or exceeding, the number of lattice nuclei in a given volume.
• the modeling process starts with the consideration of a metal lattice in a hydrogen gas environment at temperature Ti and pressure pi after equilibration time teqi, e.g. a single Pd crystal in the form of a Pd nanoparticle in a D gas environment at 2 bar and room temperature.
• thermodynamic equilibria and phase stabilities are calculated with a DFT-based method such as Quantum Espresso and Atomic Simulation Environment (ASE) software packages or the open-source stochastic self-consi stent harmonic approximation (SSCHA) approach.
• ASE Quantum Espresso and Atomic Simulation Environment
• SSCHA stochastic self-consi stent harmonic approximation
• Background electron density in the vicinity of the deuteron pairs of interest are either also calculated as an extension to the above-described DFT-based modeling or estimated based on experimental and theoretical values given in the literature.
• One example of a background electron density calculation is described in Czerski et al. 2006.
• Step A2' Consider vacancy formation and diffusion (212).
• diffusion modeling techniques are applied to model the diffusion behavior of D into the Pd lattice, as well as the formation of D filled vacancies on the surface of the Pd lattice (where thermodynamically preferred) and the diffusion of such vacancies into the bulk lattice. Examples of the vacancy stabilization and diffusion modeling techniques are described in Fukai 2003, Isaeva et al. 2011, Staker 2020, and Subashiev et al. 2020.
• An alternative way to accelerate the diffusion of D-filled vacancies is to increase the surface-to-volume ratio e.g. by making the size of nanoparticles smaller (e.g. below 10 nm).
• the model is used to determine a suitable combination of environmental parameters such as pressure p2, temperature T2, diffusion time t eq 2, and surface-to-volume-ratio (e.g. as represented in nanoparticle diameter d) that results in a PdxVacyDz material with a Vac:Pd ratio of at least 1 : 10 and a D:Pd ratio of at least 8: 10.
• some deuteron pairs then exhibit a proximity in the range of 70- 110pm.
• PdD with such a larger number of vacancies is also known as Pd in a superabundant vacancy phase or delta phase. If a Pd x Vac y D z material with a high vacancy content forms under the chosen condition and after time t eq 2, then the above- mentioned phonon mode calculations need to be updated to reflect what is now effectively a ternary material (treating the regular vacancies as an alloying component).
• Step A3 Determine oscillator characteristics such as phonon modes and photon absorption of the resulting lattice (213).
• Step A Estimate state transition rates for quantum systems of interest in the sample in the absence of strong couplings (202).
• the nuclear states available for each nuclide in the sample are identified and the state transition rates are modeled under the assumption of isolation (i.e. assuming the absence of strong couplings).
• He-4> state of the four-nucleon-configuration of deuteron pairs in Pd vacancies is calculated based on the proximity and the screening potential achieved in the lattice configuration, as determined in the previous modeling step.
• the expected transition rate is calculated, as described in US provisional patent application No. 63/186,249. Since at this stage no couplings to interacting quantum systems are yet considered, this state transition rate corresponds to the transition rate of an isolated pair of deuterons at the given proximity and screening potential.
• Step C Model the intermediate variables “enhancement of coupling strengths” due to coherent stimulation (203).
• the coupling strengths between all quantum systems of interest are determined under equilibrium conditions (intermediate variables).
• the coupling strengths between all quantum systems of interest after stimulation via coherent oscillators are determined and stored in separate variables or a single array of values.
• the coherent oscillator is a laser with wavelength p , pulse energy E p , pulse length t p , repetition rate r p , and spot size A p .
• stimulation is included in the modeling process that increases the coupling strengths between (initially weakly) coupled quantum systems.
• the addition of a laser is considered that is directed at a normal angle at the sample lattice described above and where the quantum systems are nuclei
• the photons from the laser interact directly with the nuclei in the sample lattice (photon- nuclear interactions) as well as indirectly via plasmons and phonons (phonon-nuclear interactions) generated in the lattice as a result of the photon bombardment.
• the abovedescribed interactions between nuclei and coherent oscillators lead to indirect (second and higher order) couplings between nuclei. Different laser configurations (such as those resulting in different pulse lengths) will cause different coupling strengths.
• the impact of the laser pulses on the sample can also be modified by applying nanostructured coatings to the sample that change/enhance the light-matter interaction.
• the resulting photon-nuclear interactions and phonon- nuclear interactions - as a function of the laser parameters - are then calculated.
• Different nuclei participating in the same shared coherent oscillator modes results in enhanced coupling between such nuclei.
• this enhancement of coupling strength caused by the coherent stimulation is calculated or estimated for each pairwise combination of nuclei in the sample. Estimating thus obtained enhancement of coupling strengths depends on the oscillator characteristics (e.g. coherent photon or phonon characteristics) as well as the nuclear state characteristics of the nuclei in the sample (e.g.
• the laser parameters are chosen in such a way that an increase of phonon-mediated or photon-mediated couplings between nuclei of interest of at least 3 orders of magnitude results (e.g. from ⁇ 10 neV to > 10 peV).
• the enhanced coupling strengths require that the previously estimated transition rates - obtained on the assumption of isolated (or only very weakling interacting) quantum systems - are adjusted for the quantum dynamics, including energy transfer and conversion dynamics, caused by the couplings.
• Step D Determine energy transfer and conversion dynamics as a result of substantial coupling strengths between coupled quantum systems (204).
• the dominant energy transfer pathways — and resulting transition rates for quantum systems of interest — are determined from the previously determined coupling strengths (after all enhancements have been taken into account).
• adjusted state transition rates as well as energy transfer and conversion rates are calculated, now considering the enhanced couplings caused by the coherent stimulation of the sample.
• This process employs one or more quantum dynamical models.
• An example of such a quantum dynamical model 101 is shown in FIG. 5A. Simpler dynamical models that illustrate core principles of dynamics that can occur within coupled systems are discussed in more detail below. Given the enhanced coupling strengths, some of the resulting state transitions rates are now larger than the state transition rates considered for isolated quantum systems above.
• induced de-excitations of some quantum systems can coincide with excitations of other quantum systems - which in turn can trigger secondary reactions.
• the quantum systems are nuclei such triggered secondary reactions can include disintegration of the receiver nuclei.
• the range of secondary reactions can be determined by looking up from nuclear data, or by calculating from first principle based on the relevant nuclear physics literature, the expected behavior of thus excited nuclei upon receipt of the transferred quantum of energy.
• Step E Determine output variables “observable products” that result from induced dynamics (205).
• Such unstable excited quantum systems de-excite in a number of known ways, including by photon, neutron, or charged particle emission.
• the modeler needs to consider the expected behavior of excited states in quantum systems in the sample that were induced by coherent dynamics caused by the stimulation of the sample.
• the quantum systems when the quantum systems are nuclei the behavior of excited states, including their state lifetimes, and expected decay pathways can be looked up in nuclear databases such as NuDat, from experimental and theoretical nuclear physics literature, or simulated via nuclear codes such as nuclear shell model codes (e.g. NuShellX, ANTOINE, among others).
• nuclear databases such as NuDat
• nuclear codes such as nuclear shell model codes (e.g. NuShellX, ANTOINE, among others).
• this invention describes a modeling approach for a condensed matter sample that is stimulated to populate coherent oscillator modes in the sample that are shared across multiple quantum systems, which then cause quantum dynamics through enhanced couplings between quantum systems in the sample.
• the overall model of this process consists of an integration of several existing techniques, models, and codes in a well-defined and targeted manner.
• the overall input parameters to the system to be modeled are: (1) the materials composition of the sample (which impacts the resulting lattice or amorphic structures); (2) the environmental conditions under which the lattice forms or equilibrates (particularly temperature, pressure, and optionally applied electromagnetic fields); and (3) the type and characteristics of the coherent stimulation of the lattice to populate oscillator modes and enhance coupling strengths (e.g.
• Intermediate output variables are the rates of state transitions (rates of reactions where applicable - see discussion of nomenclature above) as a result of the stimulation applied to the sample.
• Overall output variables are the form of energy (e.g. kinetic energy of alphas) and the amount of energy (e.g. 10 3 counts of 28 MeV alphas per second per mm 3 of sample) released from the system as a result of the stimulation applied to the sample.
• certain intermediate variables such as the rates of all significant state transitions are critical, which can be expressed as a vector/an array.
• the resulting state transition rates can then be ranked to identify the dominant state transitions (and corresponding reactions where applicable). This allows the designer to evaluate how the candidate system behaves from a macroscopic point of view and allows the determination of output variables such as the amount of energy converted by the device from one form into another.
• Step F Consider alternative donor and receiver systems, affecting input variable “composition” (206).
• quantum systems when the quantum systems are nuclei, other species of quantum systems added may be nuclei of a different species (i.e. different nuclides) added as dopants , or as alloy components or as composite material components (across a range of different concentrations z across simulation cycles).
• the other nuclei can be considered as impurities or traces in the host lattice/the original sample.
• the earlier discussed modeling of lattice characteristics can then be expected to hold for all intents and purposes, despite the traces.
• what needs to be considered for certain in an adjusted sample with trace additives is what the dominant coupling strengths are, what the dominant energy transfer and conversion pathways are, and what the resulting dynamics are.
• the other nuclei that are added exhibit different sets of nuclear states, with different energy levels and state characteristics, and with their own sets of couplings to other nuclei in the sample (i.e. from and to their nuclear states) and the corresponding potential for resonant or non-resonant excitation transfer behavior.
• nuclei are introduced to the sample, e.g. as traces, that exhibit strong couplings to nuclear states of other nuclei in the sample as well as resonant or close-to-resonant energy levels, then such other nuclei can act as prominent donor or receiver systems for energy transfer and conversion dynamics upon coherent stimulation of the sample.
• modeler after going through the presented modeling steps for obtaining state transition rates in a stimulated binary system such as PdD, can then iterate over the modeling process to consider the consequences of including other nuclei in the system as impurities, traces, dopants, alloying components, or composite material components. This can then alter dominant state transitions and corresponding energy transfer and conversion pathways, and as a result, also alter the forms and amounts of energy that get released from closed coupled quantum systems in the sample.
• FIG. 8A Shown in FIG. 8A are, as an example, nuclear excited states of isotopes Li-6 and He-4 as obtained from NuDat data via a Python wrapper library.
• y-axes represent energy in keV and colors represent different decay channels.
• Fig. 8B are nuclear excited states as predicted by NuShellX code.
• FIG. 8C Shown in FIG. 8C is the entire chart of nuclide, which represents the full repertoire of building blocks that the designer can draw on in considering lattice compositions.
• each isotope selected to become part of the lattice in a given concentration can impact the lattice structure and lattice behavior (if the concentration is large enough) and exhibits different nuclear states and therefore different resonances and coupling strengths with oscillator modes.
• the designer models the PdVacD lattice previously considered now with a 0.1% content of U-238 nuclei.
• the modeler considers not only couplings between deuterons and Pd host lattice nuclei, but also between deuterons and the U-238 nuclei that now form part of the lattice, as well as between U-238 nuclei and Pd host lattice nuclei.
• the modeler finds that the presence of U-238 nuclei as candidate energy transfer receiver nuclei impacts the de-excitation parameters of nearby deuteron pairs.
• He-4> (de-excitation) is accelerated if the released energy of 24 MeV is transferred to nearby U-238 nuclei as a result of enhanced coupling strengths, thereby causing the simultaneous state transition
• the excited states of U-238 near 24 MeV are unstable and decay through particle emission, e.g. alpha emission.
• the model views the example discussed here as a sample with composition of Pd, D, and U-238 (as input variables, among others) which, under coherent stimulation and correspondingly enhanced couplings within coupled quantum systems in the sample, exhibits accelerated
• Step G Iterate and optimize (207).
• the input variables are adjusted so as to optimize the output variables.
• input variables to be adjusted include M x A y , Ti, pi, t eq i, T2, P2, t eq 2, T3, ps, te q 3, p , E p , t p , r p , A p , D and z, among others (as defined and introduced above).
• the optimized output variable is a maximized AE with, as a pre-defined criterion, the imposed constraint of not generating significant amounts of neutrons.
• the steps of the overall process can be chained together such that the model steps result in an overall model of the sample to be designed with global input variables and global output variables (and with further extensions of the device to be designed).
• the model delivers de-excitation and excitation times for all state transitions of interest as a function of the chosen composition of the lattice, the boundary/environmental conditions, and the stimulation type and characteristics.
• the input variables can be varied (manually or programmatically/automatically) and the effect on output variables observed.
• overall output parameters (such as the amount of energy leaving the closed system of the sample in a desirable form) can be expressed as a function of controllable input parameters (such as composition, environmental conditions, and stimulation characteristics).
• controllable input parameters such as composition, environmental conditions, and stimulation characteristics.
• key output variables of interest (or derived key performance indicators) across different input configurations, can be represented as a resulting "landscape" of outcomes.
• Minima and maxima of this landscape are points of interest that inform optimal outcomes i.e. an optimal set of input variable values for certain desired outcomes.
• Multiple output variables can be connected or related to one another e.g. if certain tradeoffs are preferred such as between overall energy gain and a desired energy range of emitted charged particles for instance.
• the described system and process can be used to identify the most suitable isotopes, among a group of candidate isotopes, to be used in a system for efficient energy production resulting in heat.
• different geometric arrangements of such isotopes to be used (as influenced by composition and boundary conditions during lattice formation) and their effects on the overall system dynamics and system outcomes, e.g. energy production rates, can be compared and evaluated.
• Geometric arrangements that may want to be considered, tested, and evaluated for their performance with the system and process described above include different nanostructures such as nanoparticles, nanosheets, thin-film configurations, nanopillars, nanoneedles, nanowires, nanotubes etc.
• Additional input and output variables can be added such as the materials cost of particular nuclear species chosen as input variables for the structure composition, the cost of obtaining and maintain certain environmental conditions (e.g. the cost of providing very high pressures), and the cost of the stimulation mechanism (e.g. the cost of ultrafast laser stimulation vs other mechanisms of coherent photon or phonon production).
• Additional output variables can include the type of particles that get emitted from the reactions that result from the nuclear transitions that are predominant based on the predominant energy transfer pathways as well as their ultimate economic value (e.g. in terms of the released energy that can ultimately be harnessed and utilized this way).
• a device designer may find that substituting one alloying component in a sample for another leads to a 10% reduction of the overall energy balance (i.e.
• the device designer may then find that the sample with the substituted alloying component is preferred for her device design.
• constraints can be imposed on input variables e.g. to include as candidate nuclear species only materials that are procurable within a certain price range or that do not exhibit certain hazards.
• output variables can be constrained e.g. by only accepting as valid outcomes predominant nuclear transitions that lead to charged particle emission and not neutron emission. This way, the device system derived from the simulation and optimization process can be designed in such a way that from the perspective of the designer optimal outcomes are achieved (or near- optimal outcomes), i.e. optimal outcomes along the output variables considered to be most relevant, from selecting and adjusting a set of candidate input parameters to choose from across the input variables.
• Constraints or requirements may also include, as examples, releasing at least 99% of the released energy as charged particles in the 1-5 MeV range, requiring nontoxic materials as part of the sample composition, and only requiring forms of stimulation that can be provided by commercially available means within a certain price range (e.g. commercially available laser systems), among others. Similarly, searches and optimizations can be conducted for other use cases with their own respective requirements and constraints.
• the methods for producing coherent stimulation (such as coherent photons or phonons) considered during earlier design iterations may be substituted through comparable, but more cost-effective methods that yield similar results with respect to the resulting oscillator modes and the corresponding increase in coupling strengths.
• coherent stimulation such as coherent photons or phonons
• the process of modeling, simulation, performance prediction, and optimization described here is agnostic toward the specific stimulation method employed as long as, as a result of applying the chosen stimulation method, suitable oscillator modes get populated in the lattice which enhance couplings between quantum states of quantum systems of interest (resulting in a suitable vector/array of equilibrium coupling strengths to be used in the subsequent simulation of energy transfer and conversion dynamics).
• variable or value may also refer to a sequence or an array of variables or values, as is common in the arts.
• the invention presented here provides device designers with a way to greatly extend the degrees of freedom available to them in the design of useful devices. Even if only a single excitation transfer step is considered (i.e. transfer from a first type of quantum system to a second type of quantum system) this means that energy from one kind of de-excitation transition is redirected to another de-excitation transition (the one associated with the receiver quantum system). In the case that de-excitation takes the form of a nuclear reaction, for instance, this means that a nuclear reaction A (e.g. D+D
• He-4 can lead to an outcome typically only associated with a nuclear reaction B (U- Th-234 + a). This is particularly attractive if nuclear reaction A exhibits certain attractive features such as beneficial chemical properties or comparatively easy procurability but not necessarily attractive reaction parameters and reaction outputs such as the typical reaction rates and reaction products for that reaction (e.g. neutrons).
• nuclear energy transfer editing i.e. the editing and optimizing of energy transfer pathways, as described here, overall reaction parameters and products can be changed, leading effectively to an initial reaction A exhibiting modified de-excitation parameters and products of a secondary reaction B. If that secondary reaction has more desirable products than the initial one (e.g. charged particles instead of neutrons), then the overall performance of a corresponding device is improved, compared with a device that does not make use of nonradiative energy transfer to that end.
• Suitable candidate compositions include PdVacD systems with high Vac content (between 10% and 25%) and high D:Pd ratio (> 8: 10) and added materials that can serve as stepping stones for downconversion such as Ag nuclei (see discussion below).
• a secondary consideration that can enter into the design of samples that draw on energy released from the D+D reaction is directed at the possibility of out-of-equilibrium modes of operation such as adding reactants into the sample as well as removing reaction products from the sample during operation. Both processes are possible e.g. through diffusion. This can be achieved by changes in the environmental parameters such as increased gas pressure, increased temperature and is also affected by the sample composition and geometry, e.g. nanoparticles and thin films with large surface areas facilitate diffusion of reaction products into and out of the system.
• Sequences of excitation transfer (daisy chaining): Energy transfer can also occur repeatedly (i.e. from a first type of quantum system to a second type of quantum system to a third type of quantum system etc.), thus allowing for a daisy chaining of acceptor quantum systems (and their possible induced reactions upon receipt of excitation) as long as transfers happen fast enough before the incoherent decay of one of the involved states occurs. This can be considered as the creation of “chains of excitation transfer” i.e. where excitation moves across a sequence of different species of receiver quantum systems before incoherent de-excitation takes over. What results are secondary reactions, tertiary reactions, and so on, induced by a primary reaction.
• sequencing excitation transfer - and corresponding reactions to be expected as a result further extends the options available to device designers. Specifically, it allows for making use of what can be called ‘stepping stones’ i.e. quantum states that can act as intermediaries e.g. in a repeated downconversion process or upconversion process (see discussion below). For instance, a 24 MeV quantum from a
• steps stones i.e. quantum states that can act as intermediaries e.g. in a repeated downconversion process or upconversion process (see discussion below).
• He-4> state transition can downconvert
• Upconversion Note that energy transfer can be accompanied by forms of energy conversion such as upconversion and downconversion if there is a suitable configuration of donor systems and acceptor systems that enable such dynamics.
• upconversion reactions can occur when states of acceptor quantum systems (such as nuclei e.g. Pd nuclei) are resonant with coupled donor quantum systems (such as deuteron pairs as in D2) and when coherence is maintained long enough and over a large enough coherence domain/coherence length that within the coherence time several donor quantum systems collectively/cooperatively upconvert, leading to a transfer of excitation from several donor quantum systems to fewer acceptor quantum systems.
• acceptor quantum systems such as nuclei e.g. Pd nuclei
• coupled donor quantum systems such as deuteron pairs as in D2
• An example is the transfer of multiple 24 MeV quanta from
• He- 4> de-excitations that drive a
• a dominant pathway could involve multiple
• Pd nuclei if several tens of MeV of excitation are transferred to such acceptor quantum systems, fission (asymmetric or symmetric) results whereas the exact fission products depend on the amount of energy received by the acceptor before fission taking place (and thus breaking the coherence).
• Downconversion A process analogous to upconversion, but reverse compared to above-described upconversion (where the state energy from two or more quantum systems in a coherent ensemble is transferred to a single quantum system), is dowconversion (where the state energy from one quantum system in a coherent ensemble is transferred to two or more quantum systems).
• dowconversion where the state energy from one quantum system in a coherent ensemble is transferred to two or more quantum systems.
• nuclei as quantum systems of interest, this is advantageous if the thus induced behavior of the multiple acceptor nuclei (excited by the simultaneous de-excitation of a single nuclear quantum system such as
• Energy upconversion and downconversion during nonradiative energy transfer can be thought of as somewhat analogous to an electric transformer that, for instance, converts high voltage at low current to low voltage at high current (whereas total amounts of power and energy are conserved of course).
• a downconversion process can involve a small number of high-energy quanta that gets converted (via transfer to sufficiently resonant receiver systems) to a large number of low-energy quanta.
• the method and system presented here is used to optimize the performance of such transformer-like systems i.e. systems centered around and drawing on downconversion and upconversion behavior.
• Use cases for the devices designed and optimized according to this invention can be grouped into different areas of application such as heat production for industrial purposes or electricity production for remote sensors, energy storage in metastable excited states at the atomic and nuclear level i.e. quantum batteries, and information storage and processing at the atomic and nuclear level i.e. quits, each of which come with their own sets of requirements and constraints, based on which an optimization process needs to be applied to arrive at a suitable and competitive configuration and implementation.
• Use cases can be much more specific within broad categories and with highly specific and context-dependent requirements and constraints that then drive optimization and device design processes.
• use cases are spelled out and discussed in more detail below. Note that this list of use cases is exemplary and not exhaustive. Note also that use cases can be more fine-grained and differentiated, e.g. the broad use case nuclear-to-electric conversion can include many specific, context-dependent use cases (such as, as examples, nuclear-to-electric conversion for grid scale electricity production and nuclear-to-electric conversion for remote sensor electricity production).
• the broad classes of use cases and each of the specific use cases has their own sets of requirements and constraints and their own versions of dominant designs for the particular application - therefore requiring a dedicated optimization and design process according to this invention.
• a use case is the modification of nuclear reactions towards the avoidance of neutron emission.
• the goal here is to transfer energy away from certain excited states in the sample, before their decay, that would otherwise be expected to result in neutron emission.
• What is needed to that end are receiver quantum systems that can be coupled to — sufficiently strongly for such a transfer to occur fast enough to prevent neutron emission — , and for the subsequent de-excitation to occur through channels that do not include neutron emission (e.g. charged particle emission only or mainly).
• Nuclear-to-electric conversion It can be desirable to turn released nuclear binding energy (that results from nuclear reactions or from the decay from higher nuclear excited states) into electric current.
• a wide range of technologies have been described in the literature for the conversion of kinetic energy of charged particles to electricity. Examples are so-called Venetian Blinds and alphavoltaic devices. Many of the proposed conversion devices function best if the available energy is rather predictable and within a particular energy range. This invention can aide in matching the form of energy provided by a generating device to the requirements of a conversion device, thereby increasing the efficiency of such a conversion process.
• the generation of charged particles of specific characteristics can be desirable. Certain types of charged particles and certain energy ranges of these particles may be particularly desired, as a particular electric conversion system is laid out or optimized for them.
• This invention can be employed to convert outputs from nuclear processes in such a way that specific output parameter spaces are reached that are desired for follow-on processes such as electric conversion processes.
• a practitioner identifies from the chart of nuclides those nuclides with energy levels resonant to the preceding driving reaction and with subsequent decay channels that result in the desired output reaction products.
• Driving the output product generation can also involve downconversion, upconversion, and/or multiple preceding energy transfer steps to arrive at the best combination of a driving reaction (that releases energy into the dynamic system) and output product generating reaction.
• intermediate acceptor nuclei need to be considered. Eventually the excitation energy will be received by the final acceptor nuclei which will then undergo deexcitation from the received excited state resulting in decay products that can then be used for electric conversion, tailored to the chosen energy conversion process.
• Nuclear-to-heat conversion In other applications according to this invention, nuclear excitation energy may be preferred to be converted to end products different from the ones mentioned above. Instead, nuclear excitation energy may be preferred to be converted into what manifests macroscopically as heat.
• the sequencing of nuclear state transitions where the different steps of the sequence are connected via nuclear excitation transfer, as described — is employed in a way that at the end of the sequence (even if it is a short sequence e.g. consisting of only one transfer) are excited phonon modes as the final acceptors of nuclear excitation (i.e. excitation that drives the dynamics and that originated as released and converted nuclear binding energy).
• the conversion from nuclear excitation energy to phonon excitation energy may be aided by introducing "stepping stones" i.e. intermediate acceptor nuclei that enable a sequence of nuclear excitation transfers that convert a large quantum of energy in the form of nuclear excitation (that results from an earlier nuclear reaction) into multiple smaller quanta of nuclear excitation by transferring the large quantum of energy to multiple acceptor nuclei (with corresponding energy levels that collectively allow for the acceptance of the large quantum of energy).
• these acceptor nuclei then can act as donor nuclei as the energy gets further transferred to another group of acceptor nuclei (and possibly further divided into smaller energy quanta in the process).
• Quantum batteries Particularly relevant for quantum batteries, and especially for nuclear quantum batteries, are the processes of upconversion and downconversion as designed and optimized according to this invention (see above and below for a more detailed elaboration as well as examples for corresponding simulations).
• This mismatch can be bridged if the excitation and de-excitation of quantum systems used as quantum batteries is conducted in combination with upconversion and downconversion processes e.g. when multiple low-level oscillators (e.g. eV level) get pooled toward the coupling-induced excitation of a single - or multiple — higher level quantum system (e.g. keV level). And, similarly, when the coupling-induced deexcitation of a single keV level quantum system results in the transfer of energy to multiple eV level oscillators.
• the performance of such charging and discharging processes can be modeled and simulated - and then optimized through iterations as described - by the method and system described here. This in turn informs and drives the design of high-performing devices for this use case category.
• Nuclear qubits When quantum systems are used for information storage (whereas the storage of information takes place through the storage of energy in quantum systems even if that amount of energy is small), changing the information content is an important functionality of the overall device.
• the simulation and optimization processes described here also apply to the optimization of qubit systems, including those that use nuclei as qubits i.e. nuclear qubits, where excitation and de-excitation is sought to be conducted in a controlled manner and where the overall performance of the system is sought to be optimized based on given criteria and constraints (e.g. cost, operating conditions, reliability etc.).
• phonons are used to enhance couplings between the states of quantum systems such as nearby nuclei in order to flip qubits i.e.
• Phonons can be used to that end in analogous ways to the phonon-mediated controlled excitation and de-excitation of quantum systems in energy-minded applications (as described above and below), according to this invention.
• an exemplary embodiment for a device to be designed and optimized according to this invention is a power conversion device 500.
• Power conversion device 500 includes a sample material 502 that is deposited on a substrate 501.
• the sample material 502 is a composite of thin films, comprising a 5 nm Ag-109 layer 505 and a 10 nm Pd-106 layer 503 over an area of 5 mm x 20 mm.
• the Pd thin film 503 is deposited on a 1 mm glass substrate 501 in a mixed Ar and D atmosphere, leading to a high concentration of vacancies with deuterium interstitials. A vacancy content of at least 1% is sought, ideally 10% and more.
• the Ag layer 505 is added based on well-established thin film deposition techniques. Leaking of deuterium from the sample material is prevented by coating a thin passivation layer on the sample surface where leaking may occur, or by freezing the sample through a thermoelectric cooler. Stimulation is provided by a laser 504 that provides coherent photons that couple with the sample lattice, generating coherent plasmons and phonons in the sample as a result.
• the coupling between coherent oscillators in the sample 502 and nuclear states leads to a modification of state transitions.
• this modification of state transition characteristics can be modeled as a function of laser and stimulation characteristics, taking into account collective quantum effects such as superradiance as a function of the size of the coherence domain (i.e. the size of the coupled quantum system) and feedback loops such as oscillator modes getting pumped and thus enhanced by downconversion of state transition quanta (and the corresponding coupling strengths enhanced).
• Ag-109 nuclei 507 are used as receiver quantum systems that disintegrate upon receipt of transferred excitation from a
• FIG. 10B whereas the excitation transfer occurs as a result of temporarily enhanced couplings between pairs of deuterium nuclei in the lattice as donor systems and resonant or close-to-resonant receiver systems.
• the disintegration of receiver nuclei 507 results in charged particle emission 508 which in this embodiment is captured via an alphavoltaic device 506 that is attached across the layer of receiver nuclei i.e. the Ag- 109 nuclei.
• the alphavoltaic device 506 turns the kinetic energy of charged particles 508 into an electric current that can be used to operate electric devices or can be fed into a power grid.
• the alphavoltaic device 506 is a liquid-selenium based Se-S semiconductor which is attached on top of the Ag-109 layer in close proximity of ⁇ 1 mm.
• the receiver layer 502 can be doped with further nuclei of a different species to achieve a more desirable energy range of resulting charged particles that is better matched to the peak performance of the alphavoltaic device 506.
• Output power of the system can be adjusted by controlling which region of the sample is stimulated at a given point in time.
• the laser spot size is 100 microns in diameter and the position where the laser light interacts with the sample is adjusted mechanically (by moving the sample or by moving the laser spot).
• the laser spot is moved relative to the sample to a neighboring region of the sample that has not yet participated in the reactions.
• the receiver nuclei are not provided through a separate thin-film layer but are directly embedded in the lattice with the donor systems e.g. via implantation or alloying.
• the laser as a source for the production of phonons in the sample is replaced by an electrical means of coherent phonon production in the sample.
• a device of the type described above can be implemented without moving parts in a solid-state format i.e. in a wafer-like form factor. Fabrication of the latter draws on microfabrication techniques used for other highly integrated and nanostructured products such as in MEMS, semiconductor or integrated circuit design and production.
• optimizations of the performance of the above systems include maximizing power output, and in view of maximizing power output maximizing longevity of the system, and/or minimizing cost.
• output variables can be derived as functions of input variables of the system, including the composition of the lattice, the environmental/boundary conditions, and the stimulation characteristics.
• parameters of the system can then be optimized and tested in practice. Tests in practice are fed back to the modeling process to make adjustments and refinements to the modeling process.
• the components - or zones - include a fuel storage component where fuel to be used in nuclear reactions is stored such as atoms of hydrogen or one of its isotopes. Either in the same or in a separate component, the nuclear reactions take place in a controlled or semi-controlled manner. If the latter is a separate component, then transport is arranged of the fuel atoms to the nuclear reaction component of the device (e.g. through diffusion). In the component where the nuclear reaction takes place, excitation transfer is facilitated based on the above described principles.
• Acceptor nuclei of a desired nuclear species are arranged near the donor nuclei which initially hold nuclear excitation released from the nuclear reaction. Mediated by common oscillator modes, such as common phonon modes, this nuclear excitation transfers to acceptor nuclei, triggering a secondary nuclear reaction chosen for its desirable reaction products.
• the latter can comprise charged particles of a desired kind/energy level. In an additional component of the overall system, these charged particles are then converted to electric current based on known conversion principles described in the literature.
• a solid-state form factor of such a system i.e. built into a semiconductor chip like packaging — represents an important feature as it can be designed in a compact, low-maintenance way and mass produced using common principles of mass production as used for similar devices. Illustration of modeling principles for coupled systems with excitation and deexcitation dynamics
• initial values such as initial energy levels occupied by each oscillator and coupling strengths between them represent input variables and state transition rates represent output values.
• state transition rates represent output values.
• comparable models form part of Step D.
• the input variables and output variables of Step D represent intermediate variables in the overall simulation and optimization process.
• ki, k2 are the spring constants of the three oscillators
• m is the mass of the oscillators
• xi, X2, X3 are the displacements of each oscillator
• the single dotted xi, X2, X3 are the velocities
• the double dotted xi, X2, X3 are the accelerations.
• FIG. 11 shows a single oscillator without any strong couplings to other oscillators.
• the oscillator decays as it couples very weakly to a large number of modes in the environment i.e. it is lossy.
• the calculated output variables 512 include the plot of the state occupancy probability versus time. The decay of the oscillator 512 then follows an exponential trajectory with a decay factor c.
• this oscillator decaying is equivalent to a quantum system de-exciting where the total energy of the oscillator corresponds to the state occupation probability of the quantum system.
• Such a decay corresponds to what is known as spontaneous emission.
• this behavior corresponds to the natural decay of a nuclear excited state, as is the case with the spontaneous D2 He-4 reaction in isolation (see Koonin & Nauenberg 1989).
• An example is a deuteron pair 517 embedded in a Pd lattice 516 without any significant couplings to nuclear states of other quantum systems.
• FIG. 12 shows an oscillator 1 that is strongly coupled to another oscillator, oscillator 2.
• the loss factor i.e. the decay factor c is equivalent to that of the previous example
• the actual de-excitation of oscillator 1 is much accelerated compared to the previous example.
• This acceleration of de-excitation grows further with the increase of the coupling strength between the resonant oscillators (here: kcA).
• kcA the behavior exhibited in this example is known as Rabi oscillations.
• this behavior corresponds to, for example, an accelerated de-excitation of the
• this particular configuration can be considered as a closed quantum system where energy is redistributed within the closed system without a strong pathway to escape the closed system.
• An example is a deuteron pair 517 embedded in a Pd lattice 516 with a nearby He-4 nucleus 518 and with both the deuteron pair and the He-4 nucleus participating in the same coherent oscillator mode such as a phonon mode. If the coupling strength becomes large enough, Rabi oscillations can occur between the coupled deuteron pair and He-4 nucleus. Note that the simulation shows how the coupling can remain substantially lower in energy than the energy that gets transfer through the mediation of the coupling. Still, a higher coupling strength leads to faster oscillations and therefore to faster de-excitation of an initially excited system.
• the temporary enhancement can be caused, for instance, by laser stimulation that populates phonon modes or photon modes that are common to the quantum systems and interact with the states of the quantum systems.
• the receiver nucleus is, for instance, a U- 238 nucleus which, due to its high density of states around 24 MeV, is also close-to- resonant to the
• the initial dynamics are equivalent: the deexcitation of the
• the U-238* nucleus is expected to disintegrate.
• two oscillators 517a, 517b are initially excited and one 518 is unexcited. Due to resonance between the oscillators, the two excited oscillators 517a, 517b collectively transfer their energy to the unexcited oscillator 518 once the coupling strength is increased.
• this behavior corresponds to a scenario where two deuteron pairs 517a, 517b, are embedded in a highly loaded part of lattice such as a Pd lattice (preferably in monovacancies) 516 which is then stimulated to create strong couplings between nuclear states e.g. by a laser, as described above.
• a Pd lattice preferably in monovacancies
• He-4> transition can be accelerated with the corresponding excitation of the Pd nucleus to an
• the highly excited Pd* nucleus would be expected to subsequently disintegrate - unless another excitation transfer happens at such a fast rate that it would preclude incoherent disintegration. It can be seen that if more quantum systems participate in a simultaneous upconversion process, or if energy transfer is fast enough that a receiver nucleus can receive excitation coherently repeatedly before disintegration, then very high excitations of receiver nuclei can be achieved. In nuclei such as the nuclei of Pd isotopes, this translates into disintegration in the form of increasingly more symmetric fission per the known literature on symmetric and asymmetric fission (the more symmetric the higher the excitation that causes disintegration).
• FIG. 15 shows simulation input and output variables for a scenario with three oscillators where the coupling between them is initially weak and then temporarily enhanced.
• one oscillator 517 per the initial conditions i.e. the input variables to the simulation, one oscillator 517 is initially excited and two oscillators 518a, 518b are initially unexcited. Due to resonance between the oscillators, the excited oscillator 517 transfers its energy in a distributed manner to the two unexcited oscillators 518a, 518b once the coupling strength is increased.
• this behavior corresponds to a scenario where a deuteron pair 517 is embedded in a highly loaded part of lattice 516 such as a Pd lattice (preferably in monovacancies) which is then stimulated to create strong couplings between nuclear states e.g. by a laser.
• a deuteron pair strongly couples to two resonant lattice nuclei 518a, 518b, the
• He-4> transition can be accelerated with the corresponding excitation of the two lattice nuclei (here referred to as Y) near 12 MeV each (0.5 x 24 MeV).
• lattice nuclei would then either decay incoherently or act as donor systems in further excitation transfer (and potentially a further downconversion step) if coherent excitation transfer occurs faster than incoherent decay.
• State lifetimes before incoherent decay can be looked up from nuclear data databases or simulated from nuclear codes such as nuclear shell model codes.
• follow-on excitation transfer rates can be predicted based on the coupling strengths, the degrees of resonance between the coupled systems, and superradiant enhancement of the transfer dynamics which depends on the size of the coupled systems.
• the general environment of the downconversion example and the upconversion example is similar - i.e. deuteron pairs embedded in a highly D-loaded Pd lattice and stimulated by a laser. What dynamics ensue in practice depends critically on what the vicinity looks like of the deuteron pairs that form part of the coupled quantum systems that result from the stimulation. If the dominant resonances in the coupled quantum system under consideration, at the coupling strengths that result from the stimulation, are ones associated with downconversion, then downconversion will be dominant. Similarly, if the dominant resonances in the coupled quantum system under consideration, at the coupling strengths that result from the stimulation, are ones associated with upconversion, then upconversion with dominant.
• the effective coupling strength is determined between Fe-57 nuclei in a sample, as that coupling strength results from laser stimulation.
• the sample used in this example is a single-crystal with two regions: one region 520 with only Fe-57 nuclei 526 and one region 522 with both Fe-57 nuclei 526 and Co-57 nuclei 524 (here shown with a 1 : 1 ratio).
• Photon emission from the sample at the 14 keV range is monitored via an X-ray imaging device 530 such as the Andor ikon M X-ray camera.
• the Co-57/Fe-57 region 522 of the sample is then blocked with a barrier 532 such that the camera 530 observers the edge of the two regions without receiving/detecting any photons.
• the sample is then stimulated with laser photons 534 such as to generate coherent phonons in the sample of different energy levels (across the range from 10 MHz to 5 THz).
• laser photons 534 such as to generate coherent phonons in the sample of different energy levels (across the range from 10 MHz to 5 THz).
• the delocalization of photon emission from the sample into the Fe-57 only region 520 is recorded via the X- ray imager. Delocalization occurs as a result of repeated excitation transfers across the coupled quantum systems that result from enhanced coupling strengths, caused by the laser stimulation. From the extent of delocalization at each phonon energy level, the coupling strength between the 14 keV states of coupled Fe-57 nuclei can be determined as a function of phonon energy.
• the distance covered by transferred excitation within the decay time of the nuclear state is indicative of the transfer rate, and by extension of the coupling strength driving the transfers. For instance, observing a 1 mm delocalization into the Fe-57 only region 520 that results from repeated transfer across coupled systems of a size of about 10 nm each (coherence domain resulting from the stimulation) suggests about 100,000 transfers. When observed in a Fe-57 sample, at the 14 keV line, then we also know the decay time of that state which is about 100 ns (98 ns to be precise). This corresponds to a transfer rate of about 1/fs (i.e. about 1 THz). This, in turn, corresponds to an effective coupling strength (after all enhancements) of about 1 meV.
• coupling strengths can be used, for comparable contexts, in modeling and simulation processes as described herein. They can also be compared to first principles calculations of various coupling strengths, as described above. The same principles and considerations, slightly adjusted to the particular circumstances e.g. by measuring emitted alphas instead of photons, can be applied to experimentally determining coupling strengths between other nuclear states as well as other stimulation characteristics, stimulation techniques and settings. The approach is also suitable for testing candidate sample configurations such as particular sample compositions.
• One embodiment of the invention is used to compare the data obtained through simulation with the data from experimentally tested materials.
• One embodiment of the invention is used to design new experiments or devices based on insights from simulations. Experiments can then be adjusted as a result of simulations. Simulations can then be adjusted as a result of experiments and device performance.
• an exemplary computer system 400 or network architecture that may be used to implement the system of FIG. 5 and the method of FIG. 6A of the present invention includes a processor 420, first memory 430, second memory 440, I/O interface 450 and communications interface 460. All these computer components are connected via a bus 410.
• processors 420 may be used.
• Processor 420 may be a special -purpose or a general-purpose processor.
• bus 410 connects the processor 420 to various other components of the computer system 400.
• Bus 410 may also connect processor 420 to other components (not shown) such as, sensors, and servomechanisms.
• Bus 410 may also connect the processor 420 to other computer systems.
• Processor 420 can receive computer code 415 via the bus 410.
• the term "computer code” includes applications, programs, instructions, signals, and/or data, among others.
• Processor 420 executes the computer code 415 and may further send the computer code via the bus 410 to other computer systems.
• One or more computer systems 400 may be used to carry out the computer executable instructions of this invention.
• Computer system 400 may further include one or more memories, such as first memory 430 and second memory 440.
• First memory 430, second memory 440, or a combination thereof function as a computer usable storage medium to store and/or access computer code.
• the first memory 430 and second memory 440 may be random access memory (RAM), read-only memory (ROM), a mass storage device, or any combination thereof.
• RAM random access memory
• ROM read-only memory
• mass storage device or any combination thereof.
• the mass storage device 443 includes storage drive 445 and storage media 447. Storage media 447 may or may not be removable from the storage drive 445.
• Mass storage devices 443 with storage media 447 that are removable, otherwise referred to as removable storage media, allow computer code to be transferred to and/or from the computer system 400.
• Mass storage device 443 may be a Compact Disc Memory, ZIP storage device, tape storage device, magnetic storage device, optical storage device, Micro-Electro-Mechanical Systems ("MEMS"), nanotechnological storage device, floppy storage device, hard disk device, USB drive, among others. Mass storage device 443 may also be program cartridges and cartridge interfaces, removable memory chips (such as an EPROM, or PROM) and associated sockets.
• MEMS Micro-Electro-Mechanical Systems
• the computer system 400 may further include other means for computer code to be loaded into or removed from the computer system 400, such as the input/output (“I/O") interface 450 and/or communications interface 460. Both the I/O interface 450 and the communications interface 460 allow computer code to be transferred between the computer system 400 and external devices or webservers including other computer systems. This transfer may be bi-directional or omni-direction to or from the computer system 400.
• Computer code transferred by the VO interface 450 and the communications interface 460 are typically in the form of signals, which may be electronic, electromagnetic, optical, or other signals capable of being sent and/or received by the interfaces. These signals may be transmitted via a variety of modes including wire or cable, fiber optics, a phone line, a cellular phone link, infrared (“IR”), and radio frequency (“RF”) link, among others.
• the I/O interface 450 may be any connection, wired or wireless, that allows the transfer of computer code.
• I/O interface 450 includes an analog or digital audio connection, digital video interface ("DVI”), video graphics adapter ("VGA”), musical instrument digital interface ("MIDI”), parallel connection, PS/2 connection, serial connection, universal serial bus connection (“USB”), IEEE1394 connection, PCMCIA slot and card, among others.
• the I/O interface connects to an I/O unit 455 such as a user interface, monitor, speaker, printer, touch screen display, among others.
• Communications interface 460 may also be used to transfer computer code to computer system 400.
• Communication interfaces include a modem, network interface (such as an Ethernet card), wired or wireless systems (such as Wi-Fi, Bluetooth, and IR), local area networks, wide area networks, and intranets, among others.
• the invention is also directed to computer products, otherwise referred to as computer program products, to provide software that includes computer code to the computer system 400.
• Processor 420 executes the computer code in order to implement the methods of the present invention.
• the methods according to the present invention may be implemented using software that includes the computer code that is loaded into the computer system 400 using a memory 430, 440 such as the mass storage drive 443, or through an VO interface 450, communications interface 460, or any other interface with the computer system 400.
• the computer code in conjunction with the computer system 400 may perform any one of, or any combination of, the steps of any of the methods presented herein.
• the methods according to the present invention may be also performed automatically or may be invoked by some form of manual intervention.
• the computer system 400, or network architecture, of FIG. 17 is provided only for purposes of illustration, such that the present invention is not limited to this specific embodiment.

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