JP4532302B2 - Memory element - Google Patents

Description

The present invention relates to a storage element using a magnetic substance

  In recent years, research on nonvolatile memories using magnetic materials has been actively conducted. For example, it has a laminated film composed of a magnetic layer, a tunnel insulating film, and a magnetic layer, and changes the magnetization direction of one of the two magnetic layers and stores this magnetization direction. MRAM (Magnetoresistive Random Access Memory) that reads out the stored information by detecting changes in the current value flowing through the laminated film as information has been actively studied.

  However, it is difficult for the conventional MRAM to produce a laminated structure of a magnetic material, a tunnel insulating film, and a magnetic material in a TMR (Tunnel Magneto Resistive) element part, and advanced technology is required for forming this laminated film. There is a problem that the manufacturing process is complicated.

In addition, since the current flows directly through the magnetic layer to which stored information is written, there is a problem that the tunnel insulating film and the magnetic layer are easily deteriorated and the reliability is low.
JP 2000-91668 A

An object of the present invention is easy and reliable to manufacture, and is to provide a storage element that does not require a tunnel insulating film.

In order to solve the above-described problem, the memory element of the present invention includes:
A conductive ring;
A magnetic body that penetrates the space surrounded by the ring and generates a magnetic field in which at least one of direction and size changes;
A first wiring extending from a first portion of the surface of the ring;
A second wiring extending from the second portion of the surface of the ring,
The magnetic body is formed by joining a first magnetic body whose magnetization direction and magnitude do not change and a second magnetic body whose magnetization direction and magnitude change at least one of them. Yes.

  In this specification, when referring to the first part and the second part, it is assumed that the first part and the second part are different parts.

  According to the present invention, when a current is passed through a path (there are at least two different paths) connecting the first part and the second part in the ring, a space surrounded by the ring is Under the influence of the vector potential that generates the fluctuating magnetic field penetrating therethrough, a merge point (first part or second part) of currents merged after passing through the different paths due to the Aharanov-Bohm effect (hereinafter referred to as AB effect) ) Causes a shift in the phase of the electron wave. Therefore, the value of the current flowing through the wiring from which current flows (the first wiring or the second wiring) changes depending on this phase difference. Therefore, by detecting the value of the current flowing through the wiring from which the current flows, the magnetic flux penetrating the ring can be measured, and the amount of magnetic flux generated by the magnetic material can be used as stored information.

  In addition, according to the present invention, the portion through which the current flows is the ring, which is not a magnetic body having stored information. Therefore, when the magnetic body responsible for the stored information itself is detected, the electrical breakdown occurs. Alternatively, the probability of damage can be greatly reduced. Further, unlike the conventional memory element, it is not necessary to manufacture an ultrathin tunnel insulating film with low reliability, so that the reliability of the memory element can be significantly improved.

  Further, in the memory element according to one embodiment, the ring is constituted by a single current path.

  According to the embodiment, since there are only two paths connecting the first part and the second part, it is sufficient to consider only the superposition of the currents passing through each of the two paths. The calculation of current superposition can be easily performed. Therefore, the stored information can be read easily and accurately.

  In one embodiment, at least a part of the ring is constituted by a double current path.

  Even in a memory element in which at least a part of the ring is composed of a double current path, stored information can be read by the AB effect.

  When only the magnetization direction of one magnetic material is used, two magnetization states having opposite magnetization directions and the same magnitude are generated, but a ring having conductivity based on the AB effect. When the stored information is read by detecting the current flowing through the memory, there is a problem that the two stored information cannot be distinguished. Specifically, when the theoretical curve of the magnetic flux penetrating the ring and the current I is plotted, it is an even function with respect to the origin (see FIG. 4). There is a problem that the storage state of the storage unit cannot be read only by the current value.

  According to the present invention, since the magnetic body includes the first magnetic body whose magnetization direction and magnitude do not change, a constant magnetic flux emitted from the magnetic body is always added. When the magnetic flux emitted by the magnetic material whose magnetization direction and size do not change is + χ, and the saturation magnetic flux emitted by the magnetic material for changing the magnetization direction and size is + χ and −χ, it passes through the part surrounding the ring. The magnetic flux to be made can be + 2χ and 0, which can be clearly distinguished in magnitude. Therefore, it is possible not only to avoid the case where the stored information cannot be distinguished, but also to increase the modulation of the current by the magnetic field and to read the stored information reliably and easily.

  In addition, the memory element of one embodiment includes a conductive line that generates a magnetic field for changing at least one of the magnetization direction and the magnitude of the magnetic material.

  According to the embodiment, since the conductive wire is provided, at least one of the magnetization direction and the magnitude of the magnetic body can be easily changed by the conductive wire. Further, since it is not necessary to provide an external magnetic field source for changing at least one of the direction and size of the magnetic material, the number of manufacturing steps of the memory element can be greatly reduced.

The storage device of the reference example is
A ring having conductivity, a magnetic body that passes through a space surrounded by the ring, and generates a magnetic field that changes in at least one of direction and size, and a first portion that extends from a first portion of the surface of the ring. A storage element, and a second wiring extending from the second portion of the surface of the ring,
A first conductive line extending in a first direction substantially orthogonal to the direction of the magnetic field generated by the magnetic body of the memory element;
A second conductive line extending in a second direction substantially perpendicular to the first direction and substantially perpendicular to the direction of the magnetic field generated by the magnetic body,
The storage state of the storage element is changed by a combined magnetic field of the magnetic field generated by the first conductive line and the magnetic field generated by the second conductive line.

According to the reference example, information can be accurately and precisely written in the storage element by flowing an appropriate current through the first conductive line and the second conductive line.

The storage device of the reference example is
A current interference member having a conductive ring, a first wiring extending from a first portion of the surface of the ring, and a second wiring extending from a second portion of the surface of the ring;
A drive unit that moves the current interference member relative to a storage medium in which at least one of the direction and the magnitude of magnetization is stored as storage information;
A current detection unit that detects a current flowing through the first wiring or the second wiring;
Reading the information stored in the storage medium based on the current detected by the current detection unit when the current interference member and the storage medium are relatively moving in the direction in which the stored information is stored. It is characterized by.

According to the reference example, the current interference member is driven to move in the direction in which the stored information is stored with respect to the storage medium in which at least one of the magnetization direction and the magnitude is stored as the stored information. The storage state of an arbitrary part on the storage medium can be read out.

In addition , the light emitting device of the reference example is
A conductive ring;
A magnetic body that penetrates the space surrounded by the ring and forms a magnetic field in which at least one of direction and size changes;
Wiring extending from a first portion of the surface of the ring;
One of the n-type region and the p-type region extending from the second portion of the surface of the ring;
The n-type region and the p-type region of the other of the n-type region and the p-type region joined to the end of the first conductivity type region opposite to the ring side,
A pn junction formed by the first conductivity type region and the second conductivity type region by changing at least one of a direction and a magnitude of a magnetic field penetrating the space surrounded by the ring by the magnetic body. A predetermined amount of photons are emitted from the pn junction by adjusting the current flowing through the pn junction.

According to the reference example, the amount of photons emitted from the pn junction is adjusted by modulating the magnetic flux passing through the space surrounded by the ring and adjusting the current flowing through the pn junction. Therefore, the amount of photons emitted from the pn junction can be adjusted strictly. Therefore, even with a low-voltage device, the emission intensity can be precisely adjusted to a predetermined intensity.

  In the memory element of one embodiment, the lengths of the paths connecting the first portion and the second portion in the ring are all 0.3 μm or more and 1.5 μm or less.

  According to the embodiment, the lengths of the paths connecting the first part and the second part in the ring are all 0.3 μm or more and 1.5 μm or less, and the lengths of all the paths are the phase interference length. Therefore, when the magnetic flux penetrating the ring is varied, the fluctuation of the current flowing through the wiring on the outflow side can be increased, and information can be easily read.

The storage device of the reference example, the length of the path connecting the first portion and the second portion in the ring, including those all is 0.3μm or more 1.5μm or less.

According to the storage device, the lengths of the paths connecting the first part and the second part in the ring are all 0.3 μm or more and 1.5 μm or less, and the lengths of all the paths are the phase interference length. Therefore, when the magnetic flux penetrating the ring is varied, the variation of the current flowing through the wiring on the outflow side can be increased, and information can be easily read.

In addition , the light emitting element of the reference example includes one in which the length of the path connecting the first portion and the second portion in the ring is 0.3 μm or more and 1.5 μm or less .

According to the light emitting device, the lengths of the paths connecting the first part and the second part in the ring are all 0.3 μm or more and 1.5 μm or less, and the lengths of all the paths are the phase interference length. Therefore, when the magnetic flux penetrating the ring is changed, the fluctuation of the current flowing through the pn junction portion can be increased, and the amount of photons emitted from the pn junction portion can be precisely adjusted.

  According to the memory element of the present invention, when a current is passed between the first portion and the second portion of the conductive ring, the memory element is affected by the vector potential that generates a magnetic field that penetrates the space surrounded by the ring. Thus, there is a shift in the phase of the electron wave at the merge point (first portion or second portion) of the current that has merged after passing through the different paths. Therefore, the value of the current flowing through the wiring from which current flows (the first wiring or the second wiring) changes depending on this phase difference. Therefore, by detecting the value of the current flowing through the wiring from which the current flows, the magnetic flux penetrating the ring can be measured, and the amount of magnetic flux generated by the magnetic material can be used as stored information.

  In addition, according to the present invention, the portion through which the current flows is the ring, which is not a magnetic body having stored information. Therefore, when the magnetic body responsible for the stored information itself is detected, the electrical breakdown occurs. Alternatively, the probability of damage can be significantly reduced. Further, unlike the conventional memory element, it is not necessary to manufacture an ultrathin tunnel insulating film with low reliability, so that the reliability of the memory element can be significantly improved.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  The present invention constitutes a memory element that regards the magnetization direction of a magnetic material changed by an external current as information. In the memory element of the present invention, information is rewritten by the external current, but reading of information uses interference of electrons flowing through a ring-shaped conductor wound around a magnetic body.

Electron coherence becomes prominent when the properties of electron waves appear strongly. This electron interference is based on the AB effect, and the period of the existence probability of electrons when the magnetic flux is continuously changed is flux quantum Φ ₀ = h / e (= 4.14 × 10 ⁻¹⁵ [ Wb]) (where h is the Planck constant and e is the elementary charge).

  The memory portion of the memory element of the present invention is preferably formed by bonding two types of magnetic materials. At this time, the magnetization direction of one magnetic body is changed by using word lines and bit lines stretched over the memory array, while the magnetization direction of the other magnetic body is not changed.

  The amount of magnetic flux passing through the ring-shaped conductor is determined by the synthesis of the magnetic fields generated by the two types of magnetic materials, and the amount of current flowing through the ring varies depending on the amount of magnetic flux passing through the ring. Therefore, the stored information can be read by detecting the amount of current.

  In order to see the interference of electron waves in a prominent way, it is desirable that the rings have the same shape and the same composition. In addition, since it is extremely difficult to set the positions of impurities and the like at completely symmetric positions, it is preferable that the ring is made of a substance having as high a purity as possible.

  The specific structure of the present invention will be described below.

Figure 1 is a diagram showing a storage element of one embodiment of the present invention, FIG. 2 is a diagram showing the storage device of the reference example that having a memory element illustrated in FIG.

This embodiment of the storage peripherals of the memory element and the reference example, by changing the magnetization direction of the magnetic material by the magnetic field generated by the external current, so that to change the memory state.

Hereinafter, a specific structure of the storage peripherals of the memory element and a reference example of this embodiment will be described with reference to FIGS.

  As shown in FIG. 1A, the memory element includes a ring 13 having conductivity, a magnetic body 10, a first wiring 14, and a second wiring 15.

  The ring 13 is composed of a single current path. Specifically, the ring 13 is a cylindrical member having an inner peripheral cylindrical surface and an outer peripheral cylindrical surface having a central axis substantially the same as the central axis of the inner peripheral cylindrical surface. The ring 13 is made of, for example, a metal or a semiconductor such as Si or GaAs doped with impurities.

  The first wiring 14 extends radially outward from the first portion of the outer peripheral cylindrical surface, and the second wiring 15 is opposite to the first portion with respect to the central axis of the outer peripheral cylindrical surface. Extending radially outward from the second portion on the side.

  The magnetic body 10 is inserted through the ring 13. The magnetic body 10 is formed by joining a first magnetic body 11 whose magnetization direction and magnitude change and a second magnetic body 12 whose magnetization direction and magnitude does not change. Specifically, the magnetic body 10 has a rectangular end face of the first magnetic body 11 having a substantially rectangular parallelepiped shape whose magnetization direction can be changed by a predetermined external magnetic field, and a magnetization direction at a predetermined external magnetic field. It is formed by joining the rectangular end face of the substantially rectangular parallelepiped second magnetic body 12 having a strong holding force that does not change.

  The first wiring 14 and the second wiring 15 may be made of the same material as the ring 13 or may be made of a metal or a semiconductor different from that of the ring 13. If the thickness of the ring 13 in the radial direction and the direction perpendicular to it (thickness direction) is set thin, the current fluctuation due to the fluctuation of the magnetic flux passing through the ring can be increased, and the information can be reliably obtained. And can be read accurately.

  FIG. 1B is a cross-sectional view that passes through the magnetic body 11, the magnetic body 12, and the wiring 14 of the memory element illustrated in FIG.

  In FIG. 1B, reference numeral 16 denotes a joint portion between the magnetic body 11 and the magnetic body 12. As shown in FIG. 1B, the joint 16 between the magnetic body 11 and the magnetic body 12 is covered with a ring 13.

2 (A) is a front view of a storage device of the reference example, FIG. 2 (B) is a perspective view of a storage device of this reference example.

  The storage device includes the storage element 1 of the above embodiment, a word line 21 as a first conductive line, and a bit line 22 as a second conductive line.

As shown in FIGS. 2A and 2B, the word line 21 has a direction in which the magnetic body 10 extends and a first wiring 14 (second wiring 15). It extends in a direction substantially perpendicular to both of the directions. The word line 21 passes through a space surrounded by the first magnetic body 11 whose magnetization is changed by an external field and the second wiring 15 disposed on the left side of the drawing. To the word line 21, in FIG. 2 (A), the consist the plane of the upper to the current I ₁ flows downward.

On the other hand, the bit line 22 is disposed so as to pass through a position facing one end face of the first magnetic body 11 as shown in FIG. The bit line 22 is substantially perpendicular to the direction in which the magnetic body 10 extends and the direction in which the word line 21 extends, and the first wiring 14 (second wiring 15) extends. It extends in a direction parallel to the direction in which it is located. Also, to the bit line 22, in FIG. 2 (A), the adapted current I ₂ flows to the right from the plane of the left.

  The word line 21 generates the magnetic flux density vector B in the direction indicated by the arrow A in FIG. 2A, that is, concentric circles according to the right-handed screw law. It plays the role of fluctuating. The magnetic field generated by the bit line 22 according to the right-handed screw law plays a role in helping the first magnetic body 11 to cause magnetization reversal. As described above, by using the word line 21 and the bit line 22 to pass a current in a cross shape, the combined magnetic field can be made strongest at the intersection of the word line 21 and the bit line 22, and the first The magnetization of the magnetic body 11 can be easily changed.

  When a plurality of storage elements, word lines and bit lines are regularly arranged, the current is passed through the nearest word line and bit line to the storage element (memory cell) to which information is to be written. Of course, information can be written to the memory element.

  Hereinafter, a method for changing the storage state of the memory element (memory) and a reading method thereof will be described in detail with reference to FIG.

When it is desired to change the storage state, a predetermined current I ₁ , I ₂ is passed through the word line 21 and the bit line 22 to change the magnetization direction of the first magnetic body 11 and penetrate the ring 13. 11 and the total magnetic flux Φ generated by the magnetic body 12 (Φ is the product of the magnetic flux density B and the area S passing therethrough).

  For example, when the magnetic flux density fixed by the magnetic body 12 is + χ (+ represents the direction of the magnetic flux density and is the z-axis direction in FIG. 2B), the magnetic flux density emitted by the first magnetic body 11 is By changing from -χ to + χ by an external current, the total magnetic flux density penetrating the ring is varied from 0 to + 2χ. The two states of 0 and + 2χ are regarded as the storage state of the storage element.

  Next, when reading stored information, a current is caused to flow from the second wiring 15 to the first wiring 14 via the ring 13. That is, in FIG. 2B, electrons are allowed to flow from point A to point B of the ring. Thus, after passing through the point A and passing through one of the paths of the ring 13, the electron wave of the electron that has reached the point B and passing through the point A and passing through the other side of the ring 13 After passing through the path, the electron wave of the electron reaching the point B is made to interfere. Then, the stored information is read by detecting the current flowing through the first wiring 14 that fluctuates due to this interference.

  In the following, this will be explained strictly using mathematical formulas.

According to the AB effect, the interference intensity of the two electron waves depends on the vector potential vector A of the magnetic flux density vector B generated by the first magnetic body 11 and the second magnetic body 12. The interference density is: cos ² [π × (Φ / Φ ₀ )] using the flux quantum Φ ₀ = h / e (= 4.14 × 10 ⁻¹⁵ [Wb]) and the total magnetic flux Φ penetrating the ring. Become.

となる。
ここで、
ｒはｒ＝（ｘ^２＋ｙ^２）^１／２であり、

重積分は、x‐y平面内で行うものとする。 Here, as shown in FIG. 2 (B), the total magnetic flux penetrating the ring is the z-axis (where the ring thickness is w) in the direction orthogonal to the radial direction of the ring, and the radial direction of the ring. When two axes orthogonal to each other are an x-axis and a y-axis,

It becomes.
here,
r is r = (x ² + y ² ) ^1/2

The multiple integration is performed in the xy plane.

となる。したがって、第１の磁性体１１と第２の磁性体１２の磁化方向が逆向きである場合、Φ（ｚ）が、略０になり、被積分関数が、略１の値を取ることから、干渉強度は、wとなる。 Next, the thickness direction (z direction) of the ring relating to the interference intensity of the electron wave will be described. Here, the length in the thickness direction of the ring is w. At the point where the electron waves reunite, the interference effect from all z planes in the ring contributes, so that the actually observed interference intensity is centered on z = w / 2.

It becomes. Therefore, when the magnetization directions of the first magnetic body 11 and the second magnetic body 12 are opposite, Φ (z) becomes substantially 0, and the integrand takes a value of approximately 1. The interference intensity is w.

On the other hand, when the magnetization directions of the first magnetic body 11 and the second magnetic body 12 are aligned in the same direction and Φ (z) = (n + ½) Φ ₀ (n is an integer) is set. Since the integrand is substantially zero, the interference intensity is substantially zero. From this, the on / off ratio of the memory state can be made very large.

  FIG. 3 is a conceptual diagram showing that the on-off ratio of the memory state can still be increased.

  Each of the three graphs indicated by C, D and E in FIG. 3A represents the probability amplitude of interference at different points on the z-axis indicated by C, D and E in FIG. It shows that the relative phase angle is slightly different due to the difference in magnetic flux density.

Note that the horizontal axis of the graph of FIG. 3A represents a value obtained by dividing the magnetic flux Φ penetrating the ring on the z = w / 2 plane by the magnetic flux quantum Φ ₀ . In FIG. 3A, the vicinity of Φ / Φ ₀ = 0 represents the case where the magnetization directions of the two magnetic materials described above are opposite, and the vicinity of Φ / Φ ₀ = 1/2 (0.5). The case where the magnetization direction of two magnetic bodies is facing the same direction is represented.

FIG. 3C is a graph showing the sum of C, D, and E in FIG. In FIG. 3C, the probability amplitude is normalized to 1. As shown in FIG. 3 (C), for example, a point in _{Φ / Φ 0 = 1/2} , at the point in Φ / Φ _{0 = 0,} the ratio is very large.

  Here, when the thickness w of the ring-shaped conductor shown in FIG. 3B is increased, modes with different relative phase angles of π / 2 or more are mixed, and a superposition of these many modes occurs. You will not be able to see any significant peaks. Therefore, it is desirable to take w as small as possible. Specifically, although it depends on the magnitude of the magnetic flux penetrating the ring-shaped region, for example, when it is set to 1 μm or less, it works effectively.

と導出されることができ、次の関係が成立することになる。

Assuming that the ring-shaped conductor 13 is composed of a circle having no thickness (ideal circle) in the radial direction and the direction perpendicular thereto, there is a quantum mechanical gap between the flowing current I and the magnetic flux Φ. When the flow of probability (current) is an electromagnetic field when the electron wave function is Ψ (its complex conjugate is Ψ ^* ), the vector potential is vector A, and the effective mass of the electron in the ring 13 is m ^*. From Schrodinger's wave equation

And the following relationship is established.

  This equation means that the magnetic flux penetrating the ring 13 has a great influence on the current flowing through the wiring on the outflow side. The present invention uses this property to read stored information.

FIG. 4 is a graph showing the relationship in which the current is proportional to two cosine functions. In FIG. 4, the horizontal axis represents Φ / Φ ₀ and the vertical axis represents the current I.
From this equation, the condition for strengthening interference is Φ = nΦ ₀ (n is an integer), and the condition for weakening is Φ = (n + 1/2) Φ ₀ (n is an integer).

  When the constant magnetic field penetrates the ring 13, the intensity of the electron interference at the point B in FIG. 1A can be changed by continuously changing the radius of the ring 13.

  It should be noted that the length of the ring 13 needs to be about the phase interference length in order to detect significantly the interference of the electron waves of the electrons that have passed through the two different paths. Specifically, the phase interference length is about 50 nm for Si doped with impurities and several μm for a GaAs HEMT structure. Actually, if the length is several times the phase interference length, the effect of the interference can be detected, and the lengths of the paths connecting the first portion and the second portion in the ring 13 are all 0.3 μm or more and 1 If it is less than 0.5 μm, the interference can be observed remarkably.

  In addition, since phase interference is used, it is of course desirable to use a material having an interference length as long as possible. For example, 30 to 140 nm for Si, 0.5 to 3 μm for GaAs, metal Then, if an electron wave interference region of 0.5 μm to 1 μm is provided, interference can be observed more remarkably.

  In the following, it is assumed that the condition in which the phase interference intensity strengthens is realized when the magnetization directions of the magnetic body 11 and the magnetic body 12 are opposite to each other and cancel the magnetic field. think about.

As an example, when the radius r of the ring 13 is estimated,
When B = 0.5 [T]
When n = 1, r = 63 [nm], and when n = 10, r = 166 [nm].

When B = 0.05 [T],
When n = 1, r = 199 [nm], and when n = 10, r = 525 [nm].

  Since the phase interference length is several hundreds [nm] or less as described above, it is important to produce a necessary radius according to the saturation magnetization of the magnetic material.

  Further, in the memory element of this embodiment, as shown in FIG. 1, the shape of the ring 13 is symmetric. However, in the memory element of the present invention, the shape of the conductor ring may not be symmetric. Since the reading of the stored information is based on the AB effect, it is important that the electrons running in the ring are affected by the vector potential based on the magnetic field generated by the magnetic material inserted through the ring.

  FIG. 5 is a top view showing some of the memory elements that can be used in the present invention.

  In FIG. 5, 11 indicates a first magnetic body, and 12 indicates a second magnetic body. Reference numerals 24, 34, 44, and 54 denote first wirings, reference numerals 25, 35, 45, and 55 denote second wirings, and reference numerals 23, 33, 43, and 53 denote conductive rings. ing.

  FIG. 5A shows an example in which the lengths of the arms of the ring 23 (portions connecting the first portion and the second portion) are the same.

  FIGS. 5B and 5C are examples in which one of the arms is longer than the other, and the two paths connecting the wirings are asymmetric. Note that the degree of asymmetry of the ring shown in FIG. 5C is larger than that of the ring shown in FIG. FIG. 5D shows an example in which the shape of the ring is not a circle but a rectangle.

  According to the present invention, since no current flows directly through the magnetic material and the tunnel insulating film for storing information, the lifetime as a storage element can be greatly improved as compared with the conventional MRAM. In addition, since it is not necessary to produce an extremely thin insulating film in the production process, the number of man-hours can be significantly reduced. In addition, since the reliability of the memory element does not depend on the reliability of the insulating film, the reliability of the entire memory element can be significantly improved.

FIG. 6 is a diagram showing a magnetic disk storage device which is a specific example of the storage device of the reference example . The basic operating principle of this magnetic disk storage device is the same as the operating principle described for the storage element.

  In FIG. 6, reference numeral 61 denotes a part of the magnetic disk. The shape of the magnetic disk may not be a disk shape, but may be any shape. Reference numeral 61 denotes a part of a magnetic storage plate having an arbitrary shape.

  In FIG. 6, reference numeral 62 denotes the direction of the magnetic field of the magnetic domain of the magnetic disk. As shown in FIG. 6, in this magnetic disk storage device, the direction of the magnetic field is assumed to be upward or downward perpendicular to the disk surface.

  The storage device includes a current interference member 60, a drive unit (not shown), and a current detection unit (not shown).

  The current interference member 60 includes a conductive ring 63 made of metal or semiconductor, a first wiring 64 extending from the first portion of the outer peripheral surface of the ring, and a second portion different from the first portion of the outer peripheral surface of the ring. The second wiring 65 extends.

  Further, the drive unit moves the current interference member 60 with respect to the disk in the direction indicated by α in FIG. 6 in which stored information on the disk is stored.

  The current detection unit is configured to flow electrons from the second wiring 65 to the first wiring 64 and to detect a current flowing through the first wiring 64.

  In this storage device, information stored in the storage medium based on the current detected by the current detection unit when the current interference member 60 and the storage medium are relatively moved in the α direction in which the stored information is stored. Is read out.

  Specifically, this storage device utilizes a phenomenon in which the value of the current flowing through the first wiring 64 changes depending on the amount of magnetic flux passing through the ring 63 when reading the direction of the magnetic field in the magnetic disk surface. By detecting this change, information stored in the storage element is read out.

  According to this storage device, the current interference member 60 can move in the α direction in which stored information is stored on the surface of the disk 61 by the drive unit, so that all the information stored in the disk surface is read. Can do.

In the above SL reference example, dissipate static disc 61 has been to move the current interference member 60, in other reference example, dissipate static current interference member, so as to move the disk Of course, it is also good.

Further, in the above Symbol Reference Example, the driving unit, a current interference member 60, had adapted to move in a linear direction, in other reference example, the driving unit, a current interference member, e.g., a circle Of course, a route other than a straight line may be moved such as around the circumference.

FIG. 7 is a diagram illustrating a light-emitting element of a reference example .

  The existence probability of electrons at point B in FIG. 1 varies depending on the amount of magnetic flux Φ penetrating through the ring. As a result, under the conditions where the phases of the electrons are strengthening, the phases of the electrons passing through both arms of the ring are different by an integer multiple of 2π, and the existence probability is high, whereas under the conditions where they are weakening , The existence probability of electrons at point B is almost zero.

  This light emitting device includes a magnetic body 70, a conductive ring 73, a p-type region 74 as a first conductivity type region, an n-type region 75 as a second conductivity type region, and a wiring 77 ( 74 may be an n-type region and 75 may be a p-type region). The ring 73 is a member for causing interference due to the AB effect.

  The magnetic body 70 is inserted through the through hole of the ring 73. The magnetic body 70 is formed by joining a first magnetic body 71 and a second magnetic body 72. The first magnetic body 71 is a magnetic body whose magnetization direction is changed by a magnetic field generated by an external current, and the second magnetic body 72 is a magnetic body whose magnetization direction is not changed by an external current.

  The wiring 77 extends from the first portion of the outer peripheral surface of the ring 73, and the p-type region 74 extends from a second portion other than the first portion of the outer peripheral surface of the ring 73. The n-type region 75 is joined to the end of the p-type region 74 opposite to the ring 73.

  This light emitting element changes at least one of the direction and the magnitude of the magnetic field penetrating through the space surrounded by the ring 73 by the magnetic body 70 while flowing a current from the F point to the G point of the ring 73. A current flowing through a pn junction constituted by the p-type region 74 and the n-type region 75 is adjusted, and a predetermined amount of photons are emitted from the pn junction.

  FIG. 8 is a diagram showing energy bands of the p-type region 74 and the n-type region 75 shown in FIG.

  In FIG. 8, 84 indicates electrons in the conduction band of the n region, and 85 indicates holes in the valence band of the p region. In addition, 87 represents Fermi energy in the n region, and 88 represents Fermi energy in the p region. Further, it is assumed that a forward voltage is applied to the pn junction, and reference numeral 86 denotes photons (photons) generated by recombination of electrons and holes between the band gaps of the pn junction. Reference numeral 89 denotes an electron wave strengthened by phase interference.

となる。 The intensity of photons is proportional to the number of electrons falling from the conduction band of the n region to the valence band of the p region, and the number (probability of existence) depends on cos ² (πΦ / Φ ₀ ). The intensity of photons can be changed by changing the direction of magnetization of a magnetic material penetrating through a hollow ring or by changing the direction and magnitude of an external magnetic field in a hollow ring without a magnetic material. That is, when the photon intensity is I,

It becomes.

In the light emitting element of the reference example, the light emission intensity can be appropriately adjusted only by arbitrarily changing the external magnetic field. Therefore, the intensity of the light emitting element can be adjusted precisely.

  FIG. 9 is a diagram illustrating a detection device that detects impurities in a substance and the frequency of inelastic scattering.

  This detection device includes a ring 93 having a conductor, a first wiring 94 extending radially outward from a first portion of the outer peripheral surface of the ring 93, and a diameter from a second portion of the outer peripheral surface of the ring 93. A second wiring 95 extending outward in the direction, and a magnetic field fluctuation device 97 disposed opposite to both end faces of the ring 93 and continuously changing the magnetic field penetrating the through hole of the ring 93. The magnetic field fluctuation device 97 has an N pole 91 disposed opposite to one end face of the ring 93 and an S pole 92 disposed opposite to the other end face of the ring 93. The sample to be measured is a ring 93.

  In the case of an ideal conductor with no inelastic scattering when the magnetic field is continuously changed, the current flowing through the ring 93 draws the trigonometric function shown in FIG.

  However, it is usually difficult to completely remove inelastic scattering such as electron-phonon scattering and electron-electron scattering in a thin metal wire or in a two-dimensional electron gas system. The AB effect essentially observes the phase of the wave function, and the phase state is strongly influenced by inelastic scattering.

  This detection apparatus analyzes how much inelastic scattering occurs by comparing the AB vibration of an actually produced sample with an ideal graph. In addition, this detection device is intended to analyze the phase interference length and the interaction between electrons by looking at the temperature dependence.

  If the AB effect is used, the elementary charge e can be accurately measured.

  The accurate value of the elementary charge e is extremely important in the precise measurement of the current value when passing electrons one by one in a single electron transistor. However, the value of e (elementary charge) obtained from the experiment of the integer quantum Hall effect and the value obtained from other experiments (such as measurement of the magnetic moment of elementary particles such as electrons) differ from each other by more than an error. There is a problem that precise measurement of the electric charge e is impossible.

However, in the device composed of the memory element, the word line, and the bit line shown in FIG. 2, the Φ (magnetic flux) -I (current) graph is a periodic function having a period Φ _{0 due} to the AB effect, as shown in FIG. It becomes. From this, it is possible to measure the precise value of the elementary charge e by accurately measuring this period.

In the above you施形status and reference examples, ring having conductivity, was composed of single current path. However, in the present invention, at least a part of the ring having conductivity may be formed of a double current path, and in this case, stored information can be read by the AB effect.

It is a figure which shows the memory element of one Embodiment of this invention. It is a figure which shows the memory | storage device of a reference example . It is the conceptual diagram produced in order to demonstrate that the on-off ratio of a memory | storage state can be taken large. It is a figure which shows the relationship where the electric current which flows through a ring material is proportional to 2 articles | strands of a cosine function. It is a figure which shows some of the memory elements which can be used for this invention. It is a figure which shows the magnetic disc memory | storage device which is a specific example of the memory | storage device of a reference example . It is a figure which shows the light emitting element of a reference example . It is a figure which shows the energy band of the pn junction part of the said light emitting element. It is a figure which shows the detection apparatus which detects the impurity in a substance, and the frequency of inelastic scattering.

DESCRIPTION OF SYMBOLS 1 Memory element 10 Magnetic body 11 1st magnetic body 12 2nd magnetic body 13,23,33,43,53,63,73,93 Ring 14,24,34,44,54,64,71,94 1st 1 wiring 15, 25, 35, 45, 55, 65, 72, 77, 95 2nd wiring 16 junction 21 word line 22 bit line 60 current interference member 61 magnetic disk 62 magnetic field direction 70 magnetic body 74 first Conductive region 75 Second conductive region 84 Electron 85 Hole 86 Photon 87 Fermi energy of n-type conductor 88 Fermi energy of p-type conductor 89 Electron wave 91 N pole 92 S pole 97 Magnetic field fluctuation device

Claims (2)

A conductive ring;
A magnetic body that penetrates the space surrounded by the ring and generates a magnetic field in which at least one of direction and size changes;
A first wiring extending from a first portion of the surface of the ring;
A second wiring extending from the second portion of the surface of the ring,
The magnetic body is formed by joining a first magnetic body in which the direction and magnitude of magnetization do not change and a second magnetic body in which at least one of the direction and magnitude of magnetization changes. Memory element. The memory element according to claim 1, wherein
The length of the path | route which connects the said 1st part and the said 2nd part in the said ring is all 0.3 micrometer or more and 1.5 micrometers or less, The memory element characterized by the above-mentioned .

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