JPS5942689A - Magnetic bubble element - Google Patents

Abstract

PURPOSE:To eliminate the unstability of the magnetic bubble erasing or contracting operation of a hairpin conductor magnetic bubble stretcher, by providing the second hairpin conductor pattern, which has a space part common to that of the first hairpin conductor pattern, adjacent to the first conductor pattern. CONSTITUTION:A magnetic bubble stretcher 2 of the first hairpin conductor pattern, a magnetic bubble detecting means 3, and the second hairpin conductor pattern 5 around the stretcher 2 are arranged so that the center space part of the second hairpin conductor pattern 5 and that of the stretcher 2 have a common part. Such constitution is given that a ratio (2W/H) of a width 2W of the space of the second hairpin conductor to a length H between the center of the hairpin conductor layer and the center of a thin film of bubble magnetic doamin materials is >=4.0. The magnetic field distribution of bias components generated by these hairpin conductor patterns is shown by Fig. The magnetic field distribution due to the second hairpin conductor pattern has a minimum part in the hairpin center space part as shown by a curve 24, and therefore, stretched bubbles are erased stably without positional shifting.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic bubble element having a hairpin-like conductor, and more particularly to a magnetic bubble element having a hairpin-like conductor for erasing or deflating a magnetic bubble or an elongated magnetic bubble.

In an element that records and stores information using magnetic bubbles (hereinafter referred to as a magnetic bubble element), in addition to means for generating and storing magnetic bubbles as information, there is also a means for reading out the presence of magnetic bubbles as information. A magnetic bubble detector is an essential functional element. In recent years, there has been a trend toward miniaturization of the diameter of magnetic bubbles used in magnetic bubble elements as storage density increases. As the diameter of the magnetic bubble to be read becomes smaller, the detection output of the magnetic bubble generally decreases accordingly. Various magnetic bubble stretchers have been proposed in order to compensate for the decrease in detection output due to miniaturization of magnetic bubbles.

Compensation of the magnetic bubble detection output using the magnetic bubble stretcher is performed as follows. A magnetic bubble that is stretched larger using a magnetic bubble stretcher (hereinafter referred to as an extended bubble) generates leakage magnetic flux that is larger than that generated from a magnetic bubble with a normal diameter.
When the magnetic bubble is linearly extended, the leakage magnetic flux from the elongated bubble increases in proportion to its elongation ratio V. General Vr-,? i! If a material for detecting the whole bundle, for example, a material exhibiting a magnetoresistive effect such as permalloy, is provided as a detection element in accordance with the length of extension of the magnetic bubble, the leakage 178
The resistance value of the detection element changes due to the bundle, and the absolute value of the change increases in proportion to the length of extension. In other words, a large magnetic bubble detection output is obtained.

There are two well-known types of 4B bubble stretchers: Firstly.

Paper presented at the Magnetics and Magnetic Materials Conference by Strauss et al. (AIP Conference Proc.
, A10.

202 (1972)) This is a chevron stretcher in which a magnetic bubble gradually stretches at the yNfK edge of a chevron pattern of a soft magnetic material such as permalloy described in vc. Second
A paper published in the Bell System Technical Journal by Nelson et al. () 3ST, J.

59, 229 (1980)) A hairpin-shaped conductor Kig described in VC, through a flow pulse, a magnetic bubble is rapidly stretched by the magnetic potential generated in the gap of this hairpin-shaped conductor. This hairpin conductor stretcher mainly consists of a magnetic bubble detector disposed in a magnetic bubble transfer path configured with a continuous circular button (hereinafter referred to as CD button) formed by selectively implanting ions into a magnetic bubble material. It is often used in the department.

The hairpin conductor stretcher rapidly stretches magnetic bubbles by applying a current pulse to the conductor, so it is possible to stop the transfer of bubbles at will even just before stretching the magnetic puzzle, and it is possible to stop the transfer of the bubbles even just before stretching the magnetic puzzle. Compared to the chevron stretcher described above, this magnetic bubble start/strucker has the feature of being able to perform arbitrary operations. Furthermore, this four-hairpin stretcher detects magnetic bubbles with a detector placed near the stretcher, and if the magnetic bubbles are not needed, the magnetic bubbles can be detected by applying a current pulse of opposite polarity to the hairpin conductor. It is possible to erase.

It is also possible to contract the elongated magnetic bubble into a normal diameter magnetic bubble with a similar flow pulse.

However, when using the conventional hairpin conductor stretcher as a magnetic bubble eraser or constrictor, it has a serious drawback of unstable operation, as explained below with reference to the drawings. .

FIG. 1 is a diagram showing a magnetic bubble detector using a conventional hairpin conductor stretcher. A magnetic material 1 capable of holding magnetic bubbles is provided with a magnetic bubble transfer path 11 capable of transferring magnetic bubbles using an in-plane rotating magnetic field formed by, for example, ion implantation. In this magnetic bubble transfer path 11, a hairpin conductor stretcher 2 and a magnetic bubble detection element 3 made of a permalloy thin film stripe magnetoresistive element or the like are arranged in the hairpin gap. It is assumed that the direction of the bias magnetic field is applied in the direction indicated by arrow HB. When the magnetic bubble is transferred to this hairpin conductor stretcher, the detector part stretches the electric wire 822 to the conductor 2.
When the magnetic bubble is pushed in the direction vL shown by the arrow 21, a stretch is detected in the magnetic bubble. Unnecessary magnetic bubbles after detection are extinguished by the opposite polarity magnetic field generated within the hairpin by applying a current pulse 23 of opposite polarity to the conductor pattern 2. This often causes unnecessary magnetic bubbles 42 to remain around the @magnetic bubble transfer path. The presence of unnecessary magnetic bubbles around the transmission path causes major malfunctions of the magnetic bubble element.

The causes of the presence of unnecessary magnetic bubbles when the magnetic bubbles disappear will be explained with reference to FIG. 2 (I--(q)).

As shown in Figure 2 (5), 24 hairpins 2 are used to extend the
(The magnetic bubble 4 exists inside the pin 7'.

Next, when a magnetic current pulse of opposite polarity for eliminating the elongated magnetic bubble is applied to the entire hairpin conductor 2, a magnetic field as shown in FIG. The gap between the hairpin conductors is uneven due to the bias magnetic field, so the internal elongated magnetic bubble becomes unstable in position. Therefore, from the 211th MI (C) VC diagram 1, a part of the elongated magnetic bubble in the hairpin gap moves in the more stable direction of the magnetic field distribution (in this case, the direction of the sound outside the hairpin conductor), and the elongated magnetic bubble Kupur's single note v, 41v = protrudes outside the hairpin conductor. On the other hand, a portion 40 of the elongated magnetic bubble inside the hairpin is finally cut off at the bottom due to the increase in the α-Ias magnetic field. As a result, unnecessary magnetic holes and bubbles are generated outside the hairpin conductor, that is, in the vicinity of the transfer path 11. In addition, when contracting the long magnetic bubble, the H
A malfunction such as shrinking after one stroke easily occurs.

For purposes of the present invention, conventional hairpin conductors ffH? +, /
'7'' Le Stretcher's Nitrous Nopuru Erase Waka L <
[+1y#i Hairpin conductor P air capable of stable cancellation/contraction type M which eliminates instability of operation) (Pull cancellation heat'') The object of the present invention is to provide a stone aerobic bubble element that has all the features.

The eZ bubble element according to the present invention includes a magnetic material thin film that holds and acts as a magnetic material, a magnetic material thin film provided with an IC on the abrasive layer 1, and Transfer route VC West 11
゜Allowed magnetic bubble detection means Q) Has a first hairpin-shaped conductor button in the vicinity (7, the first σ) Has a gap common to the gap of the hairpin-shaped conductor button Second
The principle of the present invention will be described in detail with reference to the drawings.

First, the basic concept of the present invention will be explained with reference to FIG.

The hairpin-shaped conductor (tongue 5) shown in FIG. 3 (5) has a distance 2W between the centers of its conductor stripes that is somewhat larger than that of the conventional one. When the magnetic field distribution becomes larger, the generated magnetic field distribution generated in the hairpin-shaped conductor part will become smaller in the generated magnetic field (i.e., the potential minimum It has been clarified through calculations etc. by the applicant that this occurs.

Therefore, as shown in FIG. 3(5), when the elongated magnetic nozzle 4 is present in the central gap of the hairpin-shaped conductor 5,
Magnetic field distribution "f" in figure (13): When applied in the direction of magnetization of the magnetic nozzle, the magnetic 7J-tension becomes minimum in the central gap, so the magnetic field moves away from the gap between the particles. As shown in Figure 3 (q), the magnetic potential becomes high throughout.

At the center gap of the conductor, the magnetic domain width becomes narrower due to the elongated magnetic bubble, and finally vr-t-j disappears. In other words, it is possible to perform a reliable magnetic pull and stable erase operation.As for the contraction of an elongated magnetic bubble, the generated magnetic field is weakened and the magnetic field generation is stopped before the magnetic bubble disappears. It is equally clear that it operates more stably.

The principle of the present invention will be described in more detail with reference to FIGS. 4(5) to (D)k. The stripe width and thickness of the hairpin-shaped conductor 5 according to the present invention are as shown in FIG. 4(B).
They are 0.6 μm and 3.0 μm, respectively. At this time, as shown in FIG. 4(5), the hairpin-shaped conductor 5 is provided so that the distance between the center of the magnetic material 1 capable of holding a magnetic bubble and the center of the conductor is HK. The spacing between the hairpin conductors is 2W, measured between the centers of both conductor stripe widths.
Set it so that The magnetic field felt by the magnetic bubble from the conductor is represented by the central magnetic field of the magnetic material.1 In order to generate the minimum magnetic potential in the central gap of the hairpin conductor, which is necessary for the present invention, K is set between H and 2W. Fourth
It has become clear that a very specific relationship as shown in Figures (C) or (D) is required.

When the hairpin conductor spacing 2W is changed to 7 degrees, the maximum distance II between the magnetic material conductors that causes minimum magnetism and potential in the central gap of the hairpin field is normalized by 2W and is shown in FIG. 4 (q). It is a formula that the ratio J(/(2W)u2W approaches 0.25 as it becomes more difficult.Similarly,
The distance H is the minimum conductor spacing 2W that causes the magnetic potential at the center gap to produce minimal noise when the distance 1 is changed.
It is standardized and shown in Figure 1 (towards). Ratio 2W/l (is ■
] approaches 4.0 VC. From the above, it has become clear that the tj ratio 2W/H is required to be at least greater than 4.0 in order to stably extinguish an elongated magnetic bubble in a hairpin-shaped conductor, or cause it to stably contract in the case of a young conductor.

Furthermore, even if the batten width and thickness of the hairpin-shaped conductor 5 are changed to 2.0 μm and 0.5 μtn, respectively, the ratio 2W/H is at least 4.0 in order to produce the minimum magnetic bodential in the central gap. It became clear that something bigger was still needed.

Therefore, the structure of the magnetic bubble element according to the present invention will be described in more detail as follows. Namely.

A second hairpin conductor for magnetic bubble elimination having a common central gap is provided near the first hairpin conductor pattern forming the magnetic bubble stretcher, and the center of the conductors on both sides of the second hairpin conductor pattern is provided in the vicinity of the first hairpin conductor pattern forming the magnetic bubble stretcher. characterized in that the ratio (2W/H) of the distance (2W) to the distance (1-]) between the center of the thin film of magnetic material for bubble domain retention and the center of the film thickness of the second hairpin-shaped conductor is 4.0 or more. This is a magnetic bubble element.

Examples of the present invention will be described below. FIGS. 5(5) to (q are diagrams for explaining the first embodiment of the present invention. As shown in the plan view of FIG. A magnetic bubble in which a magnetic bubble stretcher 2, a magnetic bubble detection means 3, and a second hairpin-shaped conductor button 5 are arranged around the magnetic bubble stretcher 2 so that the central gap portion is common to the magnetic bubble stretcher 2. It is element.

FIG. 5(B) shows a cross-sectional view of the magnetic bubble element according to this example. In this embodiment, the step caused by the first hairpin-shaped conductor 2Vc is eliminated by a smoothing process, and the second hairpin-shaped conductor button 5 is provided with a bubble magnetic domain holding material thin film 1vc. The ratio (2
W/H) is configured to be 4.0 or more. The bias component magnetic field distribution generated by these hairpin-shaped conductor batons is as shown in FIG. 5(C). The first hairpin-shaped conductor batten has a sufficiently smaller batten gap than the second one, so it shows a magnetic field distribution with one valley as shown at 24' in Figure 5 (Q).From this, the magnetic bubble is extended, Next VC1
A current pulse for extinguishing the elongated magnetic bubble is applied to the second hairpin-shaped conductor button. Since the magnetic field distribution rJ due to the second hairpin-shaped conductor button has a minimum part in the central gap of the hairpin as shown in 24, it disappears stably without causing any positional shift in the elongated magnetic bubble.

Next, a second embodiment of the present invention is shown in FIG. In this embodiment, the second hairpin conductor button 5 is provided on the same surface as the first hairpin conductor button. Therefore, the conductor buttons 2 and 5 can be made of the same conductor layer. Further, the ratio 2W/H is sufficiently larger than 4.0.

A third embodiment of the invention is shown in FIG. In this example, ta
-, Ft hairpin-shaped conductor baton 2 and bubble magnetic domain material?
A magnetic structure in which the spacer of tH1A1 is dug down around the circumference of the first hairpin-shaped conductor button, the distance H between the second hairpin conductor and the bubble magnetic domain material thin film l is further reduced, and the ratio 2W/H is increased. A bubble element is shown.

A fourth embodiment of the invention is shown in FIG. In this example,
a second hairpin private conductor pattern 2 for erasing magnetic bubbles;
It is provided between the bubble magnetic domain material thin films 10. By doing this, H can be made extremely small.
When Hf, tJ'S is reduced, the generated WI per unit current is
The field strength is strong, and the erase current of the elongated magnetic bubble can be reduced.

As described above, by using the present invention, a magnetic bubble element having a magnetic bubble eraser capable of stably eliminating or contracting a long elongated magnetic bubble can be realized. Furthermore, new effects arise by implementing the present invention. Namely.

The first hairpin-shaped conductor tab and the second hairpin-shaped conductor tab are connected in series externally as necessary.

When used as a magnetic bubble stretcher.

It becomes possible to generate a magnetic field sufficient for stretching with extremely small current pulses. In this case, the ratio of 2W/H in the second hairpin conductor button is necessarily 4.
It is clear that it does not need to be greater than or equal to 0. Furthermore, in the explanation of the present invention, as an example of the magnetic bubble transfer path, one using a batten row formed by selective ion implantation was given, but it is also possible to use a batten array formed by soft magnetic material battens. It does not really specify how to form a transfer path.

[Brief explanation of drawings]

Fig. 1 μ Diagram showing a conventional example according to the present invention, Fig. 2 (5) -
(C) I-J Diagram for explaining the drawbacks of the conventional example, 3rd
Figures (A) to (C) l-r Diagrams showing the concept of the present invention, Figures 4 (a) to (to) diagrams showing the principle of the present invention, Figures 5 (5) to
(C) is a diagram showing a first embodiment of the invention, and FIGS. 6 to 8 are diagrams showing second to fourth embodiments of the invention, respectively. In the figure, 1 is a magnetic material thin film for holding magnetic bubbles, 2 is a first hairpin-shaped conductor button, 3 is a magnetic bubble detector,
4 is an elongated magnetic bubble, 5 is a second hairpin-shaped conductor button, 11 is a magnetic bubble transfer path, 21 is an arrow indicating the current pulse application direction, 22 is a magnetic bubble stretch current pulse, 23 is an extinction or contraction pulse, 24.24'i
In the magnetic field distribution of the hairpin conductor part, 40 is the part where the magnetic bubble disappears, 41 is the part where the magnetic bubble protrudes outside the hairpin conductor, and 42 is the unnecessary magnetic bubble that remains after disappearing. Figure 5

Claims (1)

[Claims] 1. A magnetic material thin film capable of holding a bubble magnetic domain, a bubble magnetic domain transfer path provided on the magnetic material thin film, and a bubble magnetic domain detection means arranged in the transfer path in the vicinity thereof. A second hairpin-shaped conductor bat having a common gap with a gap of the first hairpin-shaped conductor bat is provided in the vicinity of the first hairpin-shaped conductor bat. What was achieved f: Characteristic magnetic bubble element. 2. The distance between the centers of the conductors on both sides of the second hairpin-shaped conductor button (2W) and the distance between the center of the thin film of the magnetic material for maintaining bubble magnetic domains and the center of the film thickness of the second hairpin-shaped conductor ) The magnetic bubble element according to claim 1, characterized in that the ratio (2W/H) of the magnetic bubble element is 4.0 or more.