JPS6038794B2 - Contiguous disk type magnetic bubble element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a continuous disk type magnetic bubble element.

In storage devices that use magnetic valves (hereinafter simply referred to as bubbles) as information carriers, bubble transfer has conventionally been carried out by externally applying an in-plane rotating magnetic field to a pattern made of a magnetically sensitive film such as permalloy (hereinafter referred to as a permalloy pattern). (Conventional magnetic valve elements that perform valve transfer using such permalloy patterns are hereinafter referred to as conventional magnetic bubble elements).
However, the above-mentioned permalloy patterns must be formed with very narrow gaps between them, and the formation of these gaps becomes a limit in microfabrication and prevents an increase in storage density. Furthermore, the gaps between the permalloy patterns provide a magnetic trapping force to the bubbles being transferred, which is inconvenient for high-speed bubble transfer. In order to overcome the drawbacks of such conventional magnetic bubble elements, US Pat. A new type of magnetic bubble element called a continuous disk type magnetic bubble element has been proposed, which transfers bubbles along the .

In a continuous disk type magnetic bubble element,
In order to access bubbles efficiently, it is absolutely necessary to implement a major/minor configuration such as that already adopted in the conventional magnetic bubble element. One of the essential functional elements in a magnetic bubble element with a major/minor configuration is the ability to transfer bubbles in the minor loop to the major transfer path with good control (hereinafter referred to as transfer out), and the ability to transfer bubbles in the major transfer path to the minor transfer path with good control. This is a function to transfer to a loop (transfer in). The element that performs this function is usually called a transfer gate. Prior to explaining the present invention, the features and disadvantages of a conventional transfer gate will be explained using the drawings.

Figure 1 was published in March 1981 by R. Wolfe et al. in the Journal of Applied
Physics (Journal of Applied
Physics) Magazine No. 52, No. 3, pp. 2377-23
The transfer method shown in the paper published on page 79
This is an example of a gate. Reference numerals 1 and 2 indicate a first transfer pattern and a second transfer pattern, each consisting of a non-injected region formed on a magnetic thin film with the 111 plane as the film surface, of a cubic magnetic material capable of coercive bubbles. It is a pattern. The transfer path consisting of the edge portion on the [211] side of the first transfer pattern formed linearly in the [011] direction of the magnetic thin film is generally called a super transfer path, and provides the best transfer characteristics. It is already known that this cannot be done.

The second transfer pattern is formed in the [211] direction indicated by arrow 16.

It is well known that in the second transfer pattern formed in the [211] direction, average transfer characteristics can be obtained at both edges in the longitudinal direction of the second transfer pattern.
Such a transfer path is generally called a good transfer path. Since the magnetic thin film with the 111 plane as the pus side has 3-fold symmetry within the magnetic dense plane, the [112] side edge part of the transfer pattern formed in the [110] direction and the [101] direction The [121] side edge portions of the transfer pattern formed in are all called super transfer paths.

Also, for the same reason, [112] direction and [121]
All edge portions on both sides in the longitudinal direction of the transfer pattern formed in the direction are called good transfer paths. In the following, explanation will be continued using one of these three equivalent directions as a representative. Arrow 14 indicates the direction from the closest point 3 (first transfer pattern side) to 4 (second transfer pattern side) between the first transfer pattern and the second transfer pattern, and arrow I3 indicates the direction from the closest point 3 (first transfer pattern side) to 4 (second transfer pattern side). Effective bubble transfer direction ([011] direction)
It represents.

Reference numeral 5 represents the angle between the direction of arrow 13 and the direction of arrow 14. The first transfer pattern and the second transfer pattern are formed so that the angle 5 is approximately 1200 degrees. Arrow 15 represents the direction of the bias magnetic field.

Due to the in-plane rotating magnetic field, the bubbles are sequentially transferred through positions 7 and 8 along the edge portion of the first transfer pattern on the super transfer path side. When the bubble reaches position 9, the bubble is transferred to position 10 by applying a current pulse to the strip-shaped conductor pattern 6 in the direction of arrow 7. Thereafter, a transfer-in operation is realized in which the in-plane rotating magnetic field sequentially transfers to positions 11 and 12. On the other hand, when performing a bubble transfer-out operation, when the bubble orbiting the second transfer pattern reaches position 12, the direction of rotation of the in-plane rotating magnetic field is reversed, and the bubble passes through positions 10 and 9 sequentially and then exits. transfer to the jar transfer path. After this, the in-plane rotating magnetic field is reversed again to return to the original rotation direction. In order to perform such reversal of the in-plane rotating magnetic field, a very complex bubble drive circuit is required to achieve bidirectional transfer operation with a conventional transfer gate. SUMMARY OF THE INVENTION An object of the present invention is to provide a continuous disk type magnetic bubble element having a transfer gate that allows bubble transfer-in and transfer-out operations using a very simple bubble drive circuit.

The continuous disk type magnetic bubble element of the present invention is produced by selectively implanting ions into a magnetic thin film with the 111 plane of a cubic magnetic material capable of retaining magnetic bubbles. Measure the super transfer path side edge portion of the first transfer pattern consisting of a non-implanted region having a plurality of convex portions arranged periodically and linearly with gaps in either direction [101] or [110]. A bead-shaped non-injected non-injector is used as a transfer path and is formed in the direction of the good transfer path through a convex portion of the first transfer pattern located on the opposite side of the major transfer path and an interval portion having a predetermined gap. In a major/minor type magnetic bubble element that uses an edge portion of a second transfer pattern consisting of a region as a minor loop transfer path, the substantially band-shaped conductor pattern is provided along the first transfer pattern. Of the two edges on both sides of the conductor pattern, the first edge is located near the major transfer path, and the second edge is located near the gap between the first transfer pattern and the second transfer pattern. Alternatively, the notches are located so as to partially cover the second transfer pattern, and the second edge is formed with cuts at a period equal to the arrangement period of the first transfer pattern.

Next, the principle of the present invention will be explained based on examples.

FIG. 2 is a diagram showing a first embodiment of the present invention.

Reference numeral 25 is the first edge of the conductive pattern 17, and reference numeral 26 is the second edge. The transfer-in operation from the first transfer pattern 1 to the second transfer pattern 2 and the transfer-out operation from the second transfer pattern 2 to the first transfer pattern are performed by applying voltage to the conductor pattern 17, respectively. This is achieved using a first current pulse and a second current pulse.

Arrow 18 represents the direction of the first and second current pulses. FIG. 3 shows an example of the phase and pulse width of the current pulse.

In FIG. 3, the arrangement direction ([011] direction) of the first transfer pattern is set in the 1800 direction of the in-plane rotating magnetic field. The transfer-in operation is realized based on the following principle. When the in-plane rotating magnetic field is in the direction indicated by arrow E030, the bubble that is being transferred through the major transfer path of the first transfer pattern is at position 9 in FIG.

When a first current pulse is applied to the conductor pattern 17 in the phase range shown by the arrow 34 from this phase, the bubble is caused to move in the direction indicated by the arrow EP due to the magnetic field gradient induced by the first current pulse.
It receives driving force in the direction of 27. Arrow 33 is the direction of the in-plane rotating magnetic field when stopping the first current pulse. 1st
The bubble is sequentially transferred to positions 10 and 11 by the action of the driving force caused by the current pulse and the charged wall of the first transfer pattern. Thereafter, the bubble is transferred to the second transfer pattern through position 12 by the charged wall of the second transfer pattern, thereby realizing a transfer-in operation. On the other hand, the transfer out operation is realized based on the following principle.

When the in-plane rotating magnetic field is in the direction of arrow 32, the bubble is at position 2 in FIG. When a second current pulse is applied to the conductor pattern 17 in the phase range indicated by the arrow 34 from this phase, a local disturbance of the current occurs around the notch 24 provided in the second edge 26, and the current pulse at the position 21 A magnetic field distribution is induced such that is a valley in the magnetostatic potential. The bubble thus remains trapped at position 21 while the second current pulse is applied. When the second current pulse ends, the in-plane rotating magnetic field points in the direction of arrow 33, and at this time, a charged wall is formed in the first transfer pattern 1 that attracts the bubble at position 21. Therefore, as the charged wall moves by the in-plane rotating magnetic field, the bubbles are transferred to the final jar transfer path through the position 22, thereby realizing a transfer-out operation. According to the principle of the present invention as described above, transfer-in and transfer-out operations can be performed only by current pulses applied to the conductor pattern without reversing the in-plane rotating magnetic field, making the bubble drive circuit extremely simple. can do.

FIG. 4 shows a second embodiment of the present invention, in which the magnetic field gradient from position 9 to position 1 is strengthened to transfer bubbles.
In order to perform the finning operation stably, the first edge 2
5 also has 30 notches.

FIG. 5 shows a third embodiment of the present invention in which an opening 41 is provided in the conductive pattern 17 in addition to the notches on the first and second edges.

In this embodiment, when the first current pulse in the direction of the arrow 18 is applied to the conductor pattern 17, the current distribution is disturbed around the barrier part 41, and a magnetic field is generated such that the position 10 becomes a valley of the magnetostatic potential. distribution is induced. Therefore, the bubble can be transferred from position 9 to position 10 very stably. FIG. 6 shows a fourth embodiment of the present invention in which the shape of the first transfer pattern 42 is changed.

FIG. 7 shows a fifth embodiment of the present invention in which the shape of the first transfer pattern 43 and the shape of the notch 24 on the second edge are changed.

FIG. 8 shows an embodiment of the present invention in which the transfer out operation is performed by a current pulse of opposite polarity to that of the first, second, third, fourth and fifth embodiments by changing the position of the notch on the second edge. A sixth example is shown.

In this embodiment, when the bubble that is transferring the second transfer pattern reaches position 501, a current pulse in the direction of arrow 45 is applied to the conductor pattern 17. This induces a magnetic field distribution that looks like mountains. Therefore, the bubble continues to remain at position 501 while the current pulse is applied. After the current pulse is cut off, the charged wall on the first transfer pattern side realizes the transfer-out operation to the transfer path side via the position 51, as in the embodiment shown in FIG. FIG. 9 shows a seventh embodiment of the present invention in which the relative positional relationship between the first transfer pattern and the second transfer pattern 2 is changed.

In this embodiment, the transfer-in operation involves applying a current pulse in the direction of arrow 18 to the conductor pattern 17 when the bubble reaches position 62, and then applying a current pulse in the direction of arrow 45 when the bubble reaches position 63. This is achieved by applying current pulses. The transfer out operation is accomplished by applying a current pulse in the direction of arrow 45 when the bubble transferring the second transfer pattern reaches position 64. As described above, by using the present invention, transfer-in and transfer-out operations can be performed only by current pulses applied to the conductor pattern without reversing the rotating magnetic field, making the bubble drive circuit extremely simple. Can be done.

The shapes of the first transfer pattern, second transfer pattern, conductor pattern, etc. are shown in Figures 2, 4, 5, 6, and 7.
Various shapes other than the embodiments shown in Figures 2 and 8 are possible, but all shapes that can transfer bubbles according to the principle explained using Figures 2 and 3 are suitable for use in this book. Needless to say, it is included in the invention.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a conventional transfer gate. 1 is the first transfer pattern, 2 is the second transfer pattern, 3, 4
is the closest point between the first transfer pattern and the second transfer pattern,
14 is an arrow indicating the direction of a straight line drawn from the nearest point 3 to the nearest point 4, 13 is an arrow indicating the substantial arrangement direction of the first transfer pattern, and 5 is 2 indicated by arrows 13 and 14. The angle formed by the two directions, 16, is [211
], 6 is the conductor pattern, 7 is the arrow indicating the direction of the current pulse applied to the conductor pattern, 15 is the arrow indicating the direction of the bias magnetic field, 9, 10, 11, 12 are the bubble transfer positions . FIGS. 2 and 3 are diagrams showing a first embodiment of the present invention. 17 is a conductor pattern; 18 is an arrow indicating the direction of the current pulse applied to the conductor pattern 17; 25
, 26 are the first and second edges of the conductor pattern 17, respectively.
4 is a notch provided on the second edge, 20, 21,
22 is the transfer position of the bubble, 27 is an arrow indicating the direction of the driving force received by the bubble, 30, 31, 32, 33 is an arrow indicating the direction of the rotating magnetic field, and 34, 35 is an arrow indicating the application phase of the current pulse. . FIGS. 4 to 9 are diagrams showing second to seventh embodiments of the present invention, respectively. 42 and 43 are first transfer patterns, 40
is a notch provided on the first edge; 41 is an opening provided in the conductor pattern 17; 18 is an arrow indicating the direction of the current pulse;
, 51, 63, and 64 are bubble transfer positions. Ax figure O 2 figure spear 3 figure O 4 figure spear S figure O 6 figure O 7 figure Sai 8 figure tusk? figure

Claims (1)

[Claims] 1. 111 of cubic magnetic material capable of retaining magnetic bubbles
By selectively implanting ions onto a magnetic thin film with a film surface of The edge portion on the super transfer path side of the first transfer pattern consisting of a non-implanted region having convex portions is used as a major transfer path, and the convex portion of the first transfer pattern located on the opposite side of the major transfer path is used in advance. A major-minor type magnetic bubble that uses the edge part of a second transfer pattern consisting of bead-shaped non-injected areas formed in the direction of the positive transfer path through interval parts having predetermined intervals as a minor loop transfer part. In the element, a substantially band-shaped conductor pattern is provided along the first transfer pattern, and among two edges on both sides of the conductor pattern, a first edge is located near the major transfer path. and the second edge is located at the first edge.
The edge is located near the gap between the transfer pattern and the second transfer pattern or so as to cover a part of the second transfer pattern, and the second edge has an arrangement period of the first transfer pattern. A contiguous disk type magnetic bubble element characterized in that notches are formed at a period equal to .