JPS608550B2 - Cylindrical domain element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic memory element using a cylindrical structure.

When a uniform bias magnetic field of an appropriate magnitude is applied to a magnetic film such as garnet, which has an axis of easy magnetization in the direction perpendicular to its surface, a cylindrical magnetic domain consisting of a single domain wall with a direction of magnetization opposite to that of the surrounding area is created in the magnetic film. It is known that it can be done.

When a magnetic field gradient is applied to this cylindrical magnetic domain, the cylindrical magnetic domain moves along the magnetic field gradient. By using this property, it is possible to realize a magnetic storage book. The most commonly used method for moving the cylindrical magnetic domain is to arrange soft magnetic thin film patterns such as the letters T and 1 on a magnetic film and apply a rotating magnetic field in the in-plane direction of the magnetic film.

In order to realize a cylindrical magnetic domain element used in a magnetic storage device, a means for generating, detecting, and erasing the cylindrical magnetic domain is required in addition to the simple movement of the cylindrical domain.

Furthermore, the cylindrical element has a major loop and a minor loop.
- A method is generally used to shorten access time by providing two types of transfer paths called loops. This method is called the major/minor method (M/m method).
M/m) type cylindrical magnetic element requires a transfer gate to transfer the cylindrical magnetic domain between the major loop and the minor loop, or a replicator (r in replica) to divide the cylindrical magnetic domain. An example of a replicator is Eye. EEE Transactions on Magnetics
ctionsonMayanagitics) No. MAC-9 Volume 4
This is illustrated in Fig-8 on page 77 (1973). However, in the replicator described above, the traveling directions of the cylindrical magnetic domains in the replicator portion are opposite to each other. Therefore, the interaction of the cylindrical magnetic domains in this portion increases, and the transfer margin of the cylindrical magnetic domains decreases. or,
This replicator stretches the cylindrical magnetic domain with a conductor loop. After the stretched cylindrical magnetic domain crosses the conductor loop, it is necessary to apply a current to cut the circular magnetic domain. However, because it takes a long time for the cylindrical magnetic domain to intersect with the conductor loop, as the bias magnetic field increases, the elongated cylindrical magnetic domain shrinks, but the cylindrical magnetic domain cannot be divided, resulting in a decrease in the operating margin. It is an object of the present invention to provide a replicator which is different in type from conventionally known replicators and which has a sufficient operating margin.

Hereinafter, it will be explained in detail using examples.

FIG. i shows a replicator section of a first embodiment of the invention.

In the replicator section, the first cylindrical domain transfer path 11 and the second cylindrical domain transfer path 12 are close to each other. What should be noted here is the transfer direction amount 3 of the first cylindrical domain transfer path 11 and the second
The transfer direction 1 umbrella of the cylindrical transfer path 12 is oriented in the same direction at the replicator center ridge 5 for the same application of the rotating magnetic field. In the conventionally reported replicators, the direction is reversed as described above. A conductor pattern 16 for stretching and dividing the cylindrical magnetic domain is further arranged in the replicator center 15. In this conductor, a conductor loop section 17 for enlarging the cylindrical magnetic domain and a conductor loop section 18 for cutting the cylindrical magnetic domain are formed in this order along the transfer direction of the cylindrical magnetic domain. The conductor pattern 16 may be formed integrally with the cylindrical domain transfer path 11 and the quantity 2 using the same material, or may be formed by overlapping the material of the ascending material. Next, the operation of the replicator in the first embodiment will be explained using figures.

In FIG. 2, it is assumed that the bias magnetic field HB21 is applied from the bottom to the top of the paper.

If the in-plane rotating magnetic field HR is applied in the direction shown at 22, the cylindrical magnetic domain 23 that has proceeded through the first cylindrical domain transfer path 11 can exist at the position shown in FIG. Next, when the rotating magnetic field rotates in the direction 31 shown in FIG.
When the enlarging current ls is passed in the direction shown by , the cylindrical magnetic domain 33 extends across both the pattern section 34 of the first cylindrical domain transfer path and the pattern section 35 of the second cylindrical domain transfer path.
Furthermore, when the rotating magnetic field rotates in the direction 41 as shown in FIG. It continues astride both the cylindrical domain transfer path and the second cylindrical domain transfer path. When the rotating magnetic field rotates in the direction 51 as shown in FIG. 5, if a cutting current lc in the direction opposite to the enlarging current ls shown in FIG. The cylindrical magnetic domain that did not exist in the center of the applicator is divided into two cylindrical magnetic domains 53 and 54. In this way, the cylindrical domain that existed in the first cylindrical domain transfer path was also divided into the second cylindrical domain transfer path, and therefore the information of the first cylindrical domain transfer path was transferred to the second cylindrical domain transfer path. This means that it has been copied to the cylindrical magnetic domain transfer path No. 2. Next, we will show how the information of the second cylindrical domain transfer path is copied to the first cylindrical domain transfer path.

In FIG. 6, it is assumed that when the direction of the rotating magnetic field is in the direction of the arrow 61, the cylindrical magnetic domain 62 is at the position shown in the figure of the second cylindrical transfer path.

Next, when the rotating magnetic field is rotated in the direction 71 as shown in FIG. 7, when a stretching current ls is applied to the conductor turtle 6 in the direction of the arrow 72, the cylindrical magnetic domain 73 forms a conductor loop as shown in FIG. It extends along the section 43 and also straddles the first cylindrical transfer path. Thereafter, as shown in FIGS. 4 and 5, when the rotating magnetic field rotates in the direction 81 as shown in FIG. 8, the cylindrical magnetic domain 82 becomes a conductor roof. I get out of the club, but the first
and the second cylindrical domain transfer path, so when the rotating magnetic field rotates in the direction 91 shown in FIG. The magnetic domain is divided into 93 and 94. In this way, the cylindrical magnetic domain information that was in the second cylindrical domain transfer path is copied to the first cylindrical domain transfer path. The replicator operates as described above, and the fact that the transfer directions of the first and second cylindrical magnetic domain transfer paths at the center of the replicator are the same brings about the following great advantages.

That is, the timing at which the cutting current 52 or 92 is caused to flow in FIG. 5 or FIG. 8 can be set not only in the direction shown by 51 or 91 but also in a wide range of timing before and after the direction. On the other hand, in the conventionally reported case where the transfer directions of the first and second cylindrical magnetic domain transfer paths are opposite, the shape of the cylindrical magnetic domain changes every moment once it has been extended, and the margin for the timing of cutting is limited to that of the present invention. It becomes narrower.

Next, it will be shown that this embodiment can also erase cylindrical magnetic domains.

In FIG. 10, the rotating magnetic field is in the direction of arrow 101,
It is also assumed that the cylindrical domain 102 is located in the second cylindrical domain transfer path. When the rotating magnetic field rotates in the direction 111 shown in FIG.

At this time, the erase current 1 is applied to the conductor 16 as shown in FIG.
When ^ is applied in the direction of arrow 121 opposite to the enlarging current ls, the cylindrical magnetic domain is erased at position 122. When a cylindrical domain is transferred from the first cylindrical domain transfer path, the first
The cylindrical magnetic domain can be erased in the same manner as shown in Figures 0-12. In this manner, the replicator according to the present invention is capable of both dividing and erasing cylindrical magnetic domains. 1st
Figure 3 shows the standard current phase relationship when performing these operations.

This is the angle in the direction of the rotating magnetic field shown at axis 8' or 131 of the graph. The enlarging current ls132 is a positive pulse, and the cutting current lc133 and the erasing current 1^134 are negative pulses, which are applied near the angle shown in the figure. FIG. 14 shows a replicator section according to a second embodiment of the present invention.

The conductor is connected to the first cylindrical domain transfer path and the second cylindrical domain transfer path as shown in FIG.
It is not necessary to pass between the cylindrical magnetic domain transfer paths and connect to the adjacent IJ bricator etc., but it may be connected from the outside of the first cylindrical magnetic domain transfer path with a conductor 141 as shown in FIG. .

At this time, the cylindrical magnetic domain expansion loop portion 142 and the cutting loop portion 143 are formed from one continuous conductor. 1st
FIG. 5 shows a replicator section in a third embodiment of the present invention. In the first and second embodiments, the center of the replicator was formed in a chevron pattern, but the center of the replicator need not be limited to the shape shown in FIG. A Y-shaped pattern as shown in Fig. 15 may be used.

Furthermore, it is also possible to construct a replicator, which is a feature of the present invention, by using a pattern in which one bit is formed by one pattern, or by using different cylindrical domain transfer patterns. Further, although only one replicator is shown in the embodiment, these replicators may of course be used in parallel.

It goes without saying that the gist of the present invention can be utilized in addition to the embodiments shown above, and a cylindrical magnetic domain element having a plicator can be constructed.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a replicator section in the first embodiment of the present invention, FIGS. 2 to 12 are plan views for explaining the operation of the first embodiment, and FIG. 13 is a plan view showing the first embodiment. In the diagram showing the timing relationship of the current pulses in the example, a is a plan view showing the replicator part, b is a diagram showing the current pulses, and the first
FIG. 4 is a plan view showing a replicator section in a second embodiment of the invention, and FIG. 15 is a plan view showing a replicator section in a third embodiment of the invention. 11...First cylindrical Shiga transfer path, 12...
Second cylindrical domain transfer path, 13, 14...Cylindrical domain transfer direction, 15...Replicator center, 16...
・Conductor, 21...Bias magnetic field, 22, 31, 41
, 51, 61, 71, 81, 91, 101, 111...
...Rotating magnetic field direction, 23, 33, 42, - 53,
54, 62, 73, 82, 93, 94, 102, 112
...Cylindrical magnetic domain, 32,72... Direction of current for enlarging the cylindrical magnetic domain, 34,35,151,152...
...Transfer pattern, 17,43,142...Cylindrical magnetic domain expansion gate conductor loop, 52,92...Direction of current for cutting cylindrical magnetic domain, 121...Cylindrical magnetic domain Direction of erasing current, 122...Cylindrical magnetic domain erasing position, 131...Angle of rotating magnetic field, 132...
Current for enlarging cylindrical magnetic domain, 133...Current for cutting cylindrical magnetic domain, 134...Current for erasing cylindrical magnetic domain, 18,143
・・・・・・Conductor loop for cutting cylindrical magnetic domains. Collar 'Electric SasaZ Boxed Spear i Figure Catch Diagram Multiple S Figure Multiple D Exposure 7 Figure E 8 Figure Shiba 9 Figure Blind 'o Box Spear 〃Figure Multiple 1 Oto Box Blind '3 Figure Shouting Figure Groove 'S Figure

Claims (1)

[Scope of Claims] 1. A magnetic storage device having a magnetic film capable of holding cylindrical magnetic domains, a magnetic means for stably existing the cylindrical magnetic domains in the magnetic film, and a magnetic means for moving the cylindrical magnetic domains. , a first cylindrical domain transfer path, a second cylindrical domain transfer path, and a replicator formed together with a conductor pattern at a portion where these two types of transfer paths approach each other, and in the center thereof, the cylinders of the two types of transfer paths are connected to each other. and a replicator in which the magnetic domains are transferred essentially in the same direction. 2. The cylindrical magnetic domain element according to claim 1, wherein the conductor pattern at the center of the replicator is formed of a conductor loop for enlarging the cylindrical magnetic domain and a conductor loop for cutting the cylindrical magnetic domain. 3. The cylindrical magnetic domain element according to claim 2, wherein the cylindrical magnetic domain stretching conductor loop is stretched substantially perpendicular to the traveling direction of the cylindrical magnetic domain at the center of the replicator. 4. The cylindrical magnetic domain element according to claim 2, wherein the cylindrical magnetic domain cutting conductor loop is stretched substantially in the advancing direction of the cylindrical magnetic domain at the center of the replicator. 5. The cylindrical magnetic domain element according to claim 2, wherein the cylindrical magnetic domain stretching conductor loop and the cylindrical magnetic domain cutting conductor loop are stretched in directions substantially perpendicular to each other.