Fredkin gate and control method thereof

Abstract

The embodiment of the invention provides a Fredkin gate and a control method thereof, and relates to the field of reversible calculation and quantum computation.The Fredkin gate comprises a track area, a first control area, a second control area, a third control area and a fourth control area, the first control area and the second control area serve as input ends and are located on the first side of the track area, and the fourth control area is located on the second side of the track area; the third control area and the fourth control area serve as output ends and are located on the second side of the track area, the first control area and the second control area are symmetrically arranged, and the first side of the track area and the second side of the track area are symmetrically arranged; each of the first control region, the second control region, the third control region and the fourth control region comprises a first sub-region and a second sub-region, and the magnetic anisotropy constant of the first sub-region is lower than that of the second sub-region; the target bit input A and the target bit input B are connected with the target bit output A'and the target bit output B 'through the track area, so that the structure of a logic gate is simplified, additional auxiliary control is not involved, resource consumption is reduced, and cascade logic integration is facilitated.

Description

Technical Field

[0001] This invention relates to the fields of quantum computing, reversible computing, and magnetic nanotechnology, and particularly to a Fredkin gate and its control method. Background Technology

[0002] Fredkin gates are fundamental logic gates in the fields of reversible computing and quantum computing.

[0003] In the field of reversible computing, Fredkin gates effectively solve the problem of energy loss caused by information loss during operation of logic gates (such as AND and OR) in traditional von Neumann architectures (according to Landauer's principle, erasing 1 bit of information requires at least KTln2 joules of energy). Currently, Fredkin gates are generally implemented using multiple Tooffoli gates and some additional auxiliary circuits, with extra "status bits" or "history bits" added before and after each logic gate to record information before the operation, increasing the complexity of device design.

[0004] In quantum computing, qubits can exist in superposition states, and operations must satisfy unitary transformations, meaning they must be reversible. Fredkin gates are equivalent to controlled commutation gates in quantum computing and are crucial logical units for constructing quantum algorithms (such as quantum Fourier transforms, quantum search, and quantum simulations). Multiple controlled NOT gates (CNOT gates), multiple single-qubit gates (such as Hadamard gates and Phase gates), and possibly Tofoli gates are also needed for implementation.

[0005] It is evident that, in both quantum computing and reversible computing, the existing Fredkin logic gates are complex to construct, consume a lot of resources, and are not conducive to integration, making cascaded logic difficult. Summary of the Invention

[0006] This invention provides a Fredkin gate and its control method to solve the problems of complex construction, high resource consumption, and difficulty in integration of existing Fredkin logic gates, which leads to difficulties in cascading logic.

[0007] This invention provides a Fredkin door. In the planar structure of the Fredkin door, the Fredkin door includes a track area, a first control area, a second control area, a third control area, and a fourth control area. The first control area and the second control area serve as input terminals located on a first side of the track area, and the third control area and the fourth control area serve as output terminals located on a second side of the track area. The first control area and the second control area are symmetrically arranged, and the first side of the track area is symmetrically arranged with respect to the second side of the track area.

[0008] The first control region, the second control region, the third control region, and the fourth control region each include a first sub-region and a second sub-region, and the magnetic anisotropy constant of the first sub-region is lower than that of the second sub-region. The first sub-region is located outside the corresponding control region.

[0009] Both the control bit input C and the control bit output C' are located in the first sub-region, with the control bit output C' being closer to the track region. The target bit input A is located in the second sub-region of the first control region, the target bit output A' is located in the second sub-region of the third control region, the target bit input B is located in the second sub-region of the second control region, and the target bit output B' is located in the second sub-region of the fourth control region. The target bit input A and the target bit input B are connected to the target bit output A' and the target bit output B' through the track region.

[0010] Optionally, the track area includes an upper track, a middle track, and a lower track. The middle track is located between the upper track and the lower track. A first track groove is provided between the upper track and the middle track, and a second track groove is provided between the middle track and the lower track. In the thickness direction of the Fredkin door, the first track groove and the second track groove penetrate the composite structure layer of the Fredkin door.

[0011] Optionally, the first track groove and the second track groove have the same structure and are arranged symmetrically;

[0012] The first track groove includes a first rectangular groove, a first circular groove and a first trapezoidal groove. The first rectangular groove has a first circular groove at each end and a first trapezoidal groove at the middle position.

[0013] Optionally, a first barrier groove is provided on the side of the track area near the first track groove, and a second barrier groove is provided on the side of the track area near the second track groove. The upper track is located between the first barrier groove and the first track groove, and the lower track is located between the second barrier groove and the second track groove. The first barrier groove and the second barrier groove penetrate the composite structure layer of the Fredkin door.

[0014] Optionally, a first guide groove is provided between the first control area and the second control area, and a second guide groove is provided between the third control area and the fourth control area. The first guide groove is used to guide the synthetic antiferromagnetic coupled skyrmion corresponding to the target position input A and / or the target position input B into the track area. The second guide groove is used to export the synthetic antiferromagnetic coupled skyrmion to the target position output A' and / or the target position output B'. The first guide groove and the second guide groove penetrate the composite structure layer of the Fredkin gate.

[0015] Optionally, the first guide groove and the second guide groove have the same structure and are symmetrically arranged;

[0016] The first guide groove includes a second rectangular groove, a second trapezoidal groove, and a third rectangular groove. The second rectangular groove is connected to the second trapezoidal groove, and the short side of the second trapezoidal groove is close to the side of the track area. A third rectangular groove is respectively provided at the long side position of the second trapezoidal groove, at the second sub-region position close to the first control area, and at the second sub-region position close to the second control area. The second rectangular groove, the second trapezoidal groove, and the third rectangular groove of the first guide groove are used to guide the synthesized antiferromagnetic coupled skyrmions to different tracks in the track area.

[0017] Optionally, the first control area, the second control area, the third control area, and the fourth control area are all provided with a third guide groove. The third guide groove is located between the first sub-area and the second sub-area of ​​the corresponding control area, and the third guide groove penetrates the composite structure layer of the Fredkin door.

[0018] Optionally, each of the first sub-regions is provided with a third blocking groove, which is close to the track area and is positioned opposite to the location of the control bit output C'.

[0019] Optionally, in the thickness direction of the Fredkin door, the Fredkin door includes: a composite structure layer and a heavy metal layer, the composite structure layer including a first ferromagnetic layer, a non-magnetic layer and a second ferromagnetic layer stacked sequentially, and the heavy metal layer being disposed on the composite structure layer on the side close to the first ferromagnetic layer;

[0020] The magnetization direction of the first ferromagnetic layer is opposite to that of the second ferromagnetic layer, and both are perpendicular to the non-magnetic layer. Synthetic antiferromagnetic coupled skyrmions are generated in the composite structure layer. These synthetic antiferromagnetic coupled skyrmions are generated by injecting spin-polarized current into the composite structure layer.

[0021] This invention also provides a method for controlling a Fredkin gate, applied to the aforementioned Fredkin gate, the method comprising:

[0022] A synthetic antiferromagnetic coupled skyrmion is generated at the input of the Fredkin gate, and the presence or absence of the synthetic antiferromagnetic coupled skyrmion is detected at the input to obtain the logic input;

[0023] A driving current in a first direction is injected into the heavy metal layer of the Fredkin gate. The driving current in the first direction injects a spin current into the first ferromagnetic layer through the spin Hall effect, generating a spin-transfer torque on the magnetic moment. The synthesized antiferromagnetic coupled skyrmion moves from the input end through the orbital region toward the output end of the Fredkin gate. The movement range of the synthesized antiferromagnetic coupled skyrmion corresponding to the control bit input C is located within the first sub-region.

[0024] The presence or absence of the synthesized antiferromagnetic coupled skyrmion is detected at the output terminal to obtain the logic output corresponding to the logic input.

[0025] In this embodiment of the invention, the Fredkin gate simplifies the construction of logic gates by using a synthetic antiferromagnetically coupled skyrmion as an information carrier. The repulsive effect of the synthetic antiferromagnetically coupled skyrmion corresponding to the target bit corresponding to the output C' of the first sub-region can be controlled by controlling the logic of the control bit input C in each first sub-region, without involving additional auxiliary manipulation, thus reducing resource consumption. Furthermore, the Fredkin gate is symmetrically arranged overall, with the target bit input A and target bit input B connected to the target bit output A' and target bit output B' through the track region. Each track path in the track region is independent, facilitating cascaded logic integration. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is one of the structural schematic diagrams of the Fredkin gate provided in the embodiments of the present invention;

[0028] Figure 2 This is the second schematic diagram of the Fredkin gate provided in the embodiment of the present invention;

[0029] Figure 3 This is one of the schematic diagrams of skyrmion movement in a Fredkin gate provided in the embodiments of the present invention;

[0030] Figure 4This is the second schematic diagram of skyrmion movement in the Fredkin gate provided in this embodiment of the invention;

[0031] Figure 5 This is the third schematic diagram of skyrmion movement in the Fredkin gate provided in this embodiment of the invention;

[0032] Figure 6 This is the fourth schematic diagram of skyrmion movement in the Fredkin gate provided in this embodiment of the invention;

[0033] Figure 7 This is the fifth schematic diagram of skyrmion movement in the Fredkin gate provided in this embodiment of the invention;

[0034] Figure 8 This is the sixth schematic diagram of skyrmion movement in the Fredkin gate provided in this embodiment of the invention;

[0035] Figure 9 This is the seventh schematic diagram of the movement of skyrmions in the Fredkin gate provided in the embodiments of the present invention. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] The terms "first," "second," etc., used in the specification and claims of this invention are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such usage can be interchanged where appropriate so that embodiments of the invention can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, the first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0038] This invention provides a Fredkin gate, such as... Figure 1 and Figure 2As shown, in the planar structure of the Fredkin door, the Fredkin door includes a track area, a first control area, a second control area, a third control area, and a fourth control area. The first control area and the second control area serve as input terminals located on the first side of the track area, and the third control area and the fourth control area serve as output terminals located on the second side of the track area. The first control area and the second control area are symmetrically arranged, and the first side of the track area is symmetrically arranged with respect to the second side of the track area.

[0039] The first control region, the second control region, the third control region, and the fourth control region each include a first sub-region and a second sub-region, and the magnetic anisotropy constant of the first sub-region is lower than that of the second sub-region. The first sub-region is located outside the corresponding control region.

[0040] Both the control bit input C and the control bit output C' are located in the first sub-region, with the control bit output C' being closer to the track region. The target bit input A is located in the second sub-region of the first control region, the target bit output A' is located in the second sub-region of the third control region, the target bit input B is located in the second sub-region of the second control region, and the target bit output B' is located in the second sub-region of the fourth control region. The target bit input A and the target bit input B are connected to the target bit output A' and the target bit output B' through the track region.

[0041] In this embodiment, the Fredkin gate can be a Fredkin logic gate, and the track region can be rectangular. The first control region, the second control region, the third control region, and the fourth control region are located at the four vertices of the track region. Thus, the first and second control regions located on the first side of the track region serve as the input terminals of the Fredkin logic gate, and the third and fourth control regions located on the second side of the track region serve as the output terminals of the Fredkin logic gate. The first and second control regions are symmetrically arranged, and the control regions corresponding to the first and second sides of the track region are symmetrically arranged with the control regions corresponding to the second side of the track region (i.e., the third and fourth control regions), enabling reversible operation by changing the direction of the drive current. In other words, injecting a driving current in the first direction into the Fredkin logic gate causes the synthesized antiferromagnetic skyrmion in the Fredkin logic gate to move from the input end to the output end; after the logic operation of the Fredkin logic gate is completed, injecting a driving current in the second direction opposite to the first direction into the Fredkin logic gate causes the synthesized antiferromagnetic skyrmion to return to the input point along the opposite direction of the original logic operation path, that is, the synthesized antiferromagnetic skyrmion moves from the output end to the input end, realizing reversible operation.

[0042] The first, second, third, and fourth control areas each include a first sub-area and a second sub-area. These control areas have identical structures and exhibit central symmetry. Each sub-area within a different control area is equipped with a control bit input, a control bit output, a target bit input, or a target bit output. For example, the second sub-area of ​​the first control area may have a target bit input A, the second sub-area of ​​the second control area may have a target bit input B, the second sub-area of ​​the third control area may have a target bit output A', and the second sub-area of ​​the fourth control area may have a target bit input B'.

[0043] Furthermore, both the control bit input C and the control bit output C' are located in the first sub-region corresponding to each control region. The magnetic anisotropy constant of the first sub-region is lower than that of the second sub-region, meaning that the first sub-region can be a low-K region. u Zone. Low K u The region can be obtained by implanting corresponding ions to change the magnetic anisotropy constant in the ferromagnetic material using ion implantation, with a low K value set. u The role of the region is to generate larger synthetic antiferromagnetically coupled skyrmions and to create a potential barrier at its edges, thus confining the synthetic antiferromagnetically coupled skyrmions to low-k regions. u Within the region, and with the control bit output C' close to the track region, when the synthesized antiferromagnetic coupled skyrmion in the first sub-region reaches the control bit output C' position, it can repel other synthesized antiferromagnetic coupled skyrmions passing through that position (i.e., the synthesized antiferromagnetic coupled skyrmions in the second sub-region), thereby changing the track path of other synthesized antiferromagnetic coupled skyrmions in the track region and achieving the required logic output.

[0044] In one example, if input A is logic '1' and input C is logic '0', there is no corresponding synthetic antiferromagnetic skyrmion at the output C' position. Therefore, no repulsion occurs at the output C' position. The synthetic antiferromagnetic skyrmion corresponding to input A moves along the upper track of the track region to the output A', thus making the output A' logic '1'.

[0045] In another example, if input A is logic '1' and input C is logic '1', then there is a corresponding synthetic antiferromagnetic skyrmion at the output C' position. Therefore, a repulsive effect is generated at the output C' position. The synthetic antiferromagnetic skyrmion corresponding to input A is repelled by the synthetic antiferromagnetic skyrmion corresponding to output C', causing the synthetic antiferromagnetic skyrmion corresponding to input A to change its trajectory and move along the middle track of the track area to the output B', so that the output B' is logic '1'.

[0046] In other examples, inputs A and B are connected to outputs A' and B' via orbital regions. By controlling the logic of input C ('1' or '0'), the repulsive effect at the output C' position is controlled, thereby adjusting the orbital path of the synthetic antiferromagnetic coupled skyrmion corresponding to the target bit in the orbital region to achieve the desired logic output.

[0047] In this way, the Fredkin gate simplifies the construction of logic gates by using the synthetic antiferromagnetic coupled skyrmion as the information carrier. The repulsive effect of the synthetic antiferromagnetic coupled skyrmion corresponding to the target bit corresponding to the control bit output C' of the first sub-region can be controlled by controlling the logic of the control bit input C in each first sub-region without involving additional auxiliary manipulation, thus reducing resource consumption. Furthermore, the Fredkin gate is symmetrically set as a whole, and the target bit input A and target bit input B are connected to the target bit output A' and target bit output B' through the track region. Each track path in the track region is independent of each other, which facilitates the integration of cascaded logic.

[0048] Optionally, in the thickness direction of the Fredkin door, the Fredkin door includes: a composite structure layer and a heavy metal layer, the composite structure layer including a first ferromagnetic layer, a non-magnetic layer and a second ferromagnetic layer stacked sequentially, and the heavy metal layer being disposed on the composite structure layer on the side close to the first ferromagnetic layer;

[0049] The magnetization direction of the first ferromagnetic layer is opposite to that of the second ferromagnetic layer, and both are perpendicular to the non-magnetic layer. Synthetic antiferromagnetic coupled skyrmions are generated in the composite structure layer. These synthetic antiferromagnetic coupled skyrmions are generated by injecting spin-polarized current into the composite structure layer.

[0050] In this embodiment, in the thickness direction of the Fredkin gate, a heavy metal layer, a first ferromagnetic layer (FM1), a non-magnetic layer (NM), and a second ferromagnetic layer (FM2) are stacked sequentially from bottom to top, wherein the first ferromagnetic layer, the non-magnetic layer, and the second ferromagnetic layer constitute a composite structure layer. The generation of the synthesized antiferromagnetically coupled skyrmions can be described as follows:

[0051] The first and second ferromagnetic layers can be made of the same material and have the same thickness, with a non-magnetic layer between them. The magnetization direction of the first ferromagnetic layer is opposite to that of the second ferromagnetic layer, both perpendicular to the non-magnetic layer. Thus, by vertically injecting a spin-polarized current into the composite structure layer in the first region, the first skyrmions generated in the first ferromagnetic layer and the second skyrmions generated in the second ferromagnetic layer form a synthetic antiferromagnetically coupled skyrmion. Furthermore, because the magnetic skyrmions (i.e., the first and second skyrmions) in the two ferromagnetic layers (i.e., the first and second skyrmions) have opposite polarities, they are coupled together through interlayer antiferromagnetic coupling. The Macnules forces caused by the opposite polarities of the two ferromagnetic skyrmions are opposite in direction and equal in magnitude. During movement, there is no skyrmion Hall effect; that is, they always move in a straight line along the driving direction and do not deviate from the track, reducing the possibility of skyrmions annihilating upon contact with the track edge. Furthermore, the synthetic antiferromagnetically coupled skyrmion, which serves as an information carrier, possesses topological protection, and the antiferromagnetic coupling interaction between the two ferromagnetic layers gives it higher stability and reliability.

[0052] In one example, when a driving current in a first direction is injected into the heavy metal layer, a spin current is generated based on the spin Hall effect. This spin current is vertically injected into the first ferromagnetic layer through spin-orbit coupling, thereby generating a spin torque on the first skyrmion in the first ferromagnetic layer, driving the first skyrmion to move from the input end towards the output end. Simultaneously, the corresponding second skyrmion in the second ferromagnetic layer moves synchronously with the first skyrmion under the antiferromagnetic coupling effect. In other words, when a driving current in the first direction is injected into the heavy metal layer, a synthesized antiferromagnetically coupled skyrmion moves from the input end towards the output end. The movement of the synthesized antiferromagnetically coupled skyrmion is used to control logic gate operations.

[0053] Furthermore, after the logic gate operation is completed, a driving current in a second direction can be injected into the heavy metal layer, causing the synthesized antiferromagnetic coupled skyrmions to move from the output terminal towards the input terminal. In other words, the synthesized antiferromagnetic coupled skyrmions return to their initial positions for the next logic operation, achieving reversible operation. This avoids generating skyrmions with each logic operation, reducing the number of operation steps and lowering device power consumption. The reverse process only requires injecting a driving current in the second direction, making the control method very simple, and it eliminates the need for large currents to clear the skyrmions, further reducing logic gate power consumption.

[0054] Optionally, the track area includes an upper track, a middle track, and a lower track. The middle track is located between the upper track and the lower track. A first track groove is provided between the upper track and the middle track, and a second track groove is provided between the middle track and the lower track. In the thickness direction of the Fredkin door, the first track groove and the second track groove penetrate the composite structure layer of the Fredkin door.

[0055] In this embodiment, by setting a first track slot and a second track slot in the track area, the track area is divided into an independent upper track, a middle track, and a lower track. Furthermore, the first and second track slots penetrate the composite structure layer in the thickness direction, effectively blocking magnetic coupling or electromagnetic interference between the upper, middle, and lower tracks through physical separation. This avoids signal crosstalk between the synthesized antiferromagnetic coupled skyrmions when they move on different tracks, ensuring that the signals from each track are transmitted independently and accurately from the input to the output. In this way, independent transmission of multiple signal paths can be achieved without complex three-dimensional wiring or additional isolation components. Compared to the complex structure of Fredkin logic gates in the prior art, the Fredkin logic gate design provided in this embodiment is more compact, facilitating high-density integration in a planar structure, while reducing manufacturing difficulty and resource consumption, thus solving the problems of complex construction and integration difficulties in the prior art.

[0056] Furthermore, the first and second orbital slots penetrate the composite structure layer of the Fredkin gate, which can be achieved through photolithography. This can generate non-uniform magnetic moments at the corresponding positions of the orbital slots, causing the synthesized antiferromagnetically coupled skyrmions to move along a specified orbit under the repulsive effect of the non-uniform magnetic moments, thereby achieving the control of the movement path of the synthesized antiferromagnetically coupled skyrmions.

[0057] In some embodiments, the first track groove and the second track groove have the same structure and are arranged symmetrically;

[0058] The first track groove includes a first rectangular groove, a first circular groove and a first trapezoidal groove. The first rectangular groove has a first circular groove at each end and a first trapezoidal groove at the middle position.

[0059] In the plane corresponding to the first track groove, the first track grooves from left to right are respectively a first circular groove, a first rectangular groove, and a first circular groove. A first trapezoidal groove is provided on the side of the first rectangular groove near the middle track. The width of the first rectangular groove is equal to the radius of the first circular groove. The first trapezoidal groove is an isosceles trapezoid. The height of the first trapezoidal groove is three times the width of the first rectangular groove. The short side is located on the middle track and has the same width as the first rectangular groove. The long side is located on one side of the first rectangular groove.

[0060] The second track groove has the same structure as the first track groove, and the second track groove and the first track groove are symmetrically arranged about the middle track.

[0061] In one example, if input A is logic '1' and input C is logic '0', then there is no corresponding synthetic antiferromagnetic skyrmion at the output C' position, so no repulsive effect is generated at the output C' position. When the synthetic antiferromagnetic skyrmion corresponding to input A moves to the position of the first track slot, it is repelled by the non-uniform magnetic moment generated by the first track slot (mainly the first rectangular slot and the first circular slot corresponding to the first track slot), causing the synthetic antiferromagnetic skyrmion to move along the upper track of the track area to the output A', thus making the output A' logic '1'.

[0062] In another example, if input A is logic '1' and input C is logic '1', then there is a corresponding synthetic antiferromagnetic skyrmion at the output C' position. Therefore, a repulsive effect is generated at the output C' position. The synthetic antiferromagnetic skyrmion corresponding to input A is repelled by the synthetic antiferromagnetic skyrmion corresponding to output C', causing the synthetic antiferromagnetic skyrmion corresponding to input A to change its trajectory. When the synthetic antiferromagnetic skyrmion corresponding to input A moves to the position of the first track slot, it is repelled by the non-uniform magnetic moment generated by the first track slot (mainly the first circular slot and the first trapezoidal slot corresponding to the first track slot), causing the synthetic antiferromagnetic skyrmion to move along the middle track of the track area to the output B', realizing that the output B' is logic '1'.

[0063] In other examples, inputs A and B are connected to outputs A' and B' via track regions. By controlling the logic of input C ('1' or '0'), the repulsive effect at the output C' position is determined. Under the combined repulsive effect of the non-uniform magnetic moment generated at the corresponding position of the track slot on the synthesized antiferromagnetic skyrmion, the synthesized antiferromagnetic skyrmion moves along a specified track, thereby controlling the movement path of the synthesized antiferromagnetic skyrmion and thus achieving the desired logic output.

[0064] In some embodiments, a first blocking groove is provided on the side of the track area near the first track groove, and a second blocking groove is provided on the side of the track area near the second track groove. The upper track is located between the first blocking groove and the first track groove, and the lower track is located between the second blocking groove and the second track groove. The first blocking groove and the second blocking groove penetrate the composite structural layer of the Fredkin door. In other words, a first blocking groove is provided at each of the left and right ends of the upper track, and a second blocking groove is provided at each of the left and right ends of the lower track area. The first blocking groove and the second blocking groove can be circular grooves, and the circular grooves can have the same radius.

[0065] The first and second barrier grooves penetrate the composite structure layer of the Fredkin gate and can be achieved through photolithography. This can generate non-uniform magnetic moments at the corresponding positions of the barrier grooves, causing the synthesized antiferromagnetically coupled skyrmions to move along a specified track under the repulsive effect of the non-uniform magnetic moments, thereby further realizing the precise control of the movement path of the synthesized antiferromagnetically coupled skyrmions.

[0066] In one example, if input A is logic '1', input B is logic '1', and input C is logic '0', then there is no corresponding synthesized antiferromagnetic skyrmion at output C', therefore no repulsive effect occurs at output C'. When the synthesized antiferromagnetic skyrmion corresponding to input A moves to the first orbital slot, it is repelled by the non-uniform magnetic moment generated by the first orbital slot (mainly the first rectangular slot and the first circular slot corresponding to the first orbital slot), as well as by the non-uniform magnetic moment generated by the first blocking slot, causing the synthesized antiferromagnetic skyrmion to be repelled. The antiferromagnetically coupled skyrmion moves along the upper track of the orbital region to output A', making output A' a logic '1'. Furthermore, when the synthesized antiferromagnetically coupled skyrmion corresponding to input B moves to the second orbital slot, it is repelled by the non-uniform magnetic moment generated by the second orbital slot (mainly the first rectangular slot and the first circular slot corresponding to the second orbital slot), as well as by the non-uniform magnetic moment generated by the second blocking slot. This causes the synthesized antiferromagnetically coupled skyrmion to move along the lower track of the orbital region to output B', making output B' a logic '1'. Thus, the logic operation of input C·A·B=0·1·1 and output C'·A'·B'=0·1·1 is achieved.

[0067] Optionally, a first guide groove is provided between the first control area and the second control area, and a second guide groove is provided between the third control area and the fourth control area. The first guide groove is used to guide the synthetic antiferromagnetic coupled skyrmion corresponding to the target position input A and / or the target position input B into the track area. The second guide groove is used to export the synthetic antiferromagnetic coupled skyrmion to the target position output A' and / or the target position output B'. The first guide groove and the second guide groove penetrate the composite structure layer of the Fredkin gate.

[0068] In this embodiment, by setting a first guide slot and a second guide slot to space the first control area and the second control area, and to space the third control area and the fourth control area, the motion trajectory of the synthesized antiferromagnetic coupled skyrmion, which serves as the information carrier, is precisely guided. This ensures that the transmission path of the synthesized antiferromagnetic coupled skyrmion within the Fredkin gate is stable and accurate, preventing the synthesized antiferromagnetic coupled skyrmion from deviating, becoming confused, or diffusing before entering the orbital region. This ensures that the skyrmion is orderly introduced into the corresponding orbital region, providing a stable initial path for subsequent logic operations, thereby guaranteeing the reliability of the logic operations.

[0069] The first guide slot and the second guide slot penetrate the composite structure layer of the Fredkin gate to form a clear physical boundary (such as an energy barrier), strengthen the topological constraint on skyrmions, reduce external interference, and facilitate the high-density integration of logic gates, laying a stable structural foundation for cascaded logic operations.

[0070] In some embodiments, the first guide groove and the second guide groove have the same structure and are symmetrically arranged;

[0071] The first guide groove includes a second rectangular groove, a second trapezoidal groove, and a third rectangular groove. The second rectangular groove is connected to the second trapezoidal groove, and the short side of the second trapezoidal groove is close to the side of the track area. A third rectangular groove is respectively provided at the long side position of the second trapezoidal groove, at the second sub-region position close to the first control area, and at the second sub-region position close to the second control area. The second rectangular groove, the second trapezoidal groove, and the third rectangular groove of the first guide groove are used to guide the synthesized antiferromagnetic coupled skyrmions to different tracks in the track area.

[0072] The second rectangular groove is the large rectangular groove, the third rectangular groove is the small rectangular groove, and the second trapezoidal groove is an isosceles trapezoid with its short side located on the inside and having the same width as the small rectangular groove, and its long side located on the outside and having the same width as the large rectangular groove.

[0073] In one example, if input A is logic '1' and input C is logic '0', then there is no corresponding synthetic antiferromagnetic skyrmion at the output C' position, so no repulsion occurs at the output C' position. The synthetic antiferromagnetic skyrmion corresponding to input A is repelled by the non-uniform magnetic moment generated by the first guide slot (mainly the second rectangular slot and the upper third rectangular slot) in the second sub-region corresponding to the first control region, causing the synthetic antiferromagnetic skyrmion to move towards the upper track of the track region. When the synthetic antiferromagnetic skyrmion corresponding to input A moves to the position of the first track slot, it is repelled by the non-uniform magnetic moment generated by the first track slot (mainly the first rectangular slot and the first circular slot corresponding to the first track slot) and the non-uniform magnetic moment generated by the first blocking slot, causing the synthetic antiferromagnetic skyrmion to move along the upper track of the track region to the output A', thus making the output A' logic '1'.

[0074] In another example, if input A is logic '1' and input C is logic '1', then there is a corresponding synthetic antiferromagnetic skyrmion at the output C' position. Therefore, a repulsive effect is generated at the output C' position. The synthetic antiferromagnetic skyrmion corresponding to input A is repelled by the synthetic antiferromagnetic skyrmion corresponding to output C', causing the synthetic antiferromagnetic skyrmion corresponding to input A to change its trajectory and move towards the middle track of the track area. Furthermore, when the synthetic antiferromagnetic skyrmion corresponding to input A moves to the position of the first track slot, it is repelled by the non-uniform magnetic moment generated by the first track slot (mainly the first circular slot and the first trapezoidal slot corresponding to the first track slot) and by the non-uniform magnetic moment generated by the first guide slot (mainly the second trapezoidal slot), causing the synthetic antiferromagnetic skyrmion to move along the middle track of the track area to the output B', thus making the output B' logic '1'.

[0075] In another example, if input B is logic '1' and input C is logic '0', then there is no corresponding synthetic antiferromagnetic skyrmion at output C', so no repulsion occurs at output C'. The synthetic antiferromagnetic skyrmion corresponding to input B is repelled by the non-uniform magnetic moment generated by the first guide slot (mainly the second rectangular slot and the lower third rectangular slot) in the second sub-region corresponding to the second control region, causing the synthetic antiferromagnetic skyrmion to move towards the lower track of the track region. When the synthetic antiferromagnetic skyrmion corresponding to input B moves to the position of the second track slot, it is repelled by the non-uniform magnetic moment generated by the second track slot (mainly the first rectangular slot and the first circular slot corresponding to the second track slot) and the non-uniform magnetic moment generated by the second blocking slot, causing the synthetic antiferromagnetic skyrmion to move along the lower track of the track region to output B', thus making output B' logic '1'.

[0076] Optionally, the first control area, the second control area, the third control area, and the fourth control area are all provided with a third guide groove. The third guide groove is located between the first sub-area and the second sub-area of ​​the corresponding control area. The third guide groove penetrates the composite structure layer of the Fredkin door. From the outside to the inside, the cutting shape of the third guide groove includes a rectangular groove and a circular groove, and the width of the rectangular groove is equal to the radius of the circular groove.

[0077] In this embodiment, the first sub-region and the second sub-region have different functions (corresponding to the control bit and the target bit, respectively). The third guide slot can clearly delineate the boundary between the two, avoiding interference between the skyrmions related to the control bit and the skyrmions related to the target bit in the same control region. At the same time, it guides the skyrmions corresponding to the target bit to move orderly between the second sub-region and the track region, ensuring that the movement path of the skyrmions is stable and controllable, thereby ensuring the accuracy and reliability of the logic operations in the Fredkin gate.

[0078] Optionally, each of the first sub-regions is provided with a third blocking groove, which is close to the track area and is positioned opposite to the location of the control bit output C'.

[0079] In this embodiment, since the control bit output C' is located in the first sub-region and close to the track region, and the third blocking slot is opposite to C' and close to the track region, it can prevent the skyrmion corresponding to the control bit output C' from accidentally spreading to or entering the track region, thus avoiding interference with the transmission process of the skyrmion corresponding to the target bit input in the track region. At the same time, it prevents the control bit signal from being distorted due to the unexpected movement of the skyrmion, thereby ensuring the stability of the control signal and the accuracy of the logic operation in the Fredkin gate.

[0080] This invention also provides a method for controlling a Fredkin gate, applied to the aforementioned Fredkin gate, the method comprising:

[0081] A synthetic antiferromagnetic coupled skyrmion is generated at the input of the Fredkin gate, and the presence or absence of the synthetic antiferromagnetic coupled skyrmion is detected at the input to obtain the logic input;

[0082] A driving current in a first direction is injected into the heavy metal layer of the Fredkin gate. The driving current in the first direction injects a spin current into the first ferromagnetic layer through the spin Hall effect, generating a spin-transfer torque on the magnetic moment. The synthesized antiferromagnetic coupled skyrmion moves from the input end through the orbital region toward the output end of the Fredkin gate. The movement range of the synthesized antiferromagnetic coupled skyrmion corresponding to the control bit input C is located within the first sub-region.

[0083] The presence or absence of the synthesized antiferromagnetic coupled skyrmion is detected at the output terminal to obtain the logic output corresponding to the logic input.

[0084] In the Fredkin logic gate, binary logic '1' and '0' can be characterized by the presence or absence of a synthesized antiferromagnetic skyrmion. The input of binary logic can generate a synthesized antiferromagnetic skyrmion based on binary logic '1', while logic '0' does not generate a synthesized antiferromagnetic skyrmion. In cascaded logic, the synthesized antiferromagnetic skyrmion can also be inherited as input from the previous logic operation. The truth table of the Fredkin logic gate is shown in Table 1 below:

[0085] Table 1

[0086]

[0087] In the Fredkin logic gate, the generation of the synthesized antiferromagnetically coupled skyrmion is achieved by vertically injecting a spin-polarized current through a circular magnetic tunnel junction above the first ferromagnetic layer, causing a reversal of the local magnetic moment in the first ferromagnetic layer. The corresponding magnetic moment in the second ferromagnetic layer also reverses under the antiferromagnetic coupling between the two ferromagnetic layers. After removing the magnetic tunnel junction, the magnetic moment in the input region relaxes to a stable state, forming the synthesized antiferromagnetically coupled skyrmion. The synthesized antiferromagnetically coupled skyrmion is detected using the non-collinear magnetoresistance effect, with its presence representing logic '1' and its absence representing logic '0'.

[0088] Among them, the control bit input C and output C' are located at the four vertices of the rectangular layer structure. u Region, and only in the low K uThe region moves; the four control bits are completely identical; when the left end of the rectangle is the input, the control bits participate in the logic operation with the two control bits on the left, and the output is used to control the synthesis of antiferromagnetic coupled skyrmion path control during reverse operation. The reverse is also true.

[0089] The Fredkin logic gate operates by injecting a driving current into the heavy metal layer. Based on the spin Hall effect in the heavy metal, a spin current is vertically injected into the second ferromagnetic layer, driving the synthetic antiferromagnetic skyrmion to move and perform the logic operation. Furthermore, after the Fredkin logic gate operation is completed, a current in the opposite direction to the first driving current is injected into the heavy metal layer. The synthetic antiferromagnetic skyrmion returns to the input point along the reverse path of the original logic operation, meaning the synthetic antiferromagnetic skyrmion returns to its initial position, achieving reversible operation. No skyrmions are annihilated during the Fredkin logic gate operation and its inverse operation, ensuring information reliability. In addition, the Fredkin logic gate is easy to cascade and integrate, and can be directly used as the input of another logic operation based on the synthetic antiferromagnetic skyrmion, without needing to generate a synthetic antiferromagnetic skyrmion as input.

[0090] In this embodiment, the logic manipulation and reversible process were simulated and analyzed using a micromagnetic simulation method. A specific example of the simulation is a Co(1nm) / Ru(1nm) / Co(1nm) / Pt structure with a rectangular structure size of 690nm × 320nm. The driving current is 2.5 × 10⁻⁶. 11 A / m 2The Fredkin logic gate can generate a synthetic antiferromagnetic coupled skyrmion as an information carrier based on the logic input, or it can be used as a cascaded logic to generate a synthetic antiferromagnetic coupled skyrmion as an information carrier from the result of the previous logic operation. This greatly simplifies the structure compared to other Fredkin logic gates. The logic operation is achieved by injecting current along the first direction within the heavy metal layer, thereby driving the movement of the synthetic antiferromagnetic coupled skyrmion. The reversible process only requires injecting current in the opposite direction of the first driving current direction (i.e., the second driving current direction), making the control method very simple. The movement path of the synthetic antiferromagnetic coupled skyrmion mainly relies on the non-uniform repulsive effect of the void edges within the nanofilm on the synthetic antiferromagnetic coupled skyrmion for control, without involving additional auxiliary manipulation. The synthetic antiferromagnetic coupled skyrmion itself, as an information carrier, has topological protection, and the antiferromagnetic coupling interaction between the two ferromagnetic layers gives it higher stability and reliability. In a Fredkin logic gate, the synthetic antiferromagnetic coupled skyrmion movement paths of each target bit and control bit are independent. They can be directly used as inputs to the Fredkin logic gate from the end of the previous independent logic operation based on the synthetic antiferromagnetic coupled skyrmion. Therefore, the Fredkin logic gate is more conducive to cascaded logic integration.

[0091] When the input C of the first and second control areas is '0', the target position input A and the target position input B are completely independent; the synthesized antiferromagnetic coupled skyrmion in the target position input A, guided by the first, second, and third guide slots, the first blocking slot, and the first track slot, enters the output A' via the upper track; the synthesized antiferromagnetic coupled skyrmion in the target position input B, guided by the first, second, and third guide slots, the second blocking slot, and the second track slot, enters the output A' via the lower track.

[0092] When the input C of the first and second control zones is '1', when the synthesized antiferromagnetic skyrmion of the target position input A moves to the output C' of the first control zone, it is repelled by the synthesized antiferromagnetic skyrmion of the output C', changing its path and moving towards the middle track. Then, guided by the first and second track slots and the second and third guide slots, it enters the output B'. Similarly, when the synthesized antiferromagnetic skyrmion of the target position input B moves to the output C' of the second control zone, it is repelled by the synthesized antiferromagnetic skyrmion of the output C', changing its path and moving towards the middle track. Then, guided by the first and second track slots and the second and third guide slots, it enters the output A'.

[0093] In this embodiment of the invention, the Fredkin gate uses synthesized antiferromagnetically coupled skyrmions as information carriers. By manipulating the movement path of these synthesized antiferromagnetically coupled skyrmions, logical operations and reversible operations are achieved. During these processes, no synthesized antiferromagnetically coupled skyrmions are annihilated, preventing the loss of logical information and serving as a record of historical operations. This avoids the loss of logical information and increases non-volatility and reliability. The Fredkin gate implements all logical operations within a rectangular multilayer film and has its own logical operation recording function, eliminating the need for additional auxiliary devices or manipulations such as "status bits" or "history bits." Compared to conventional Fredkin gates, this significantly simplifies the device structure and operation method, and reduces energy and resource consumption. The Fredkin gate has a simple structure, is easy to operate, and has a size of only a few hundred nanometers, making it easy to integrate and suitable for logic cascading.

[0094] Specifically, in one embodiment, when input A is logic '0', input B is '0', and the control bit is '0', that is, input C·A·B = 0·0·0; the Fredkin logic gate does not synthesize an antiferromagnetically coupled skyrmion, and the output is '0'. That is, output C'·A'·B' = 0·0·0.

[0095] In one embodiment, when input A is logic '1', input B is '0', and the control bit is '0'; that is, input C·A·B = 0·1·0. The trajectory of the synthesized antiferromagnetically coupled skyrmion during the logic operation is as follows: Figure 3 As shown. Thus, the synthesized antiferromagnetic skyrmion corresponding to input A, within the second sub-region corresponding to the first control region, experiences a repulsive effect from the non-uniform magnetic moment generated by the edge of the first guide slot (mainly the second rectangular slot and the upper third rectangular slot), causing the synthesized antiferromagnetic skyrmion to move obliquely upwards (i.e., towards the upper track of the track region). Furthermore, when the synthesized antiferromagnetic skyrmion corresponding to input A reaches the position of the first track slot, it experiences a combined repulsive effect from the non-uniform magnetic moment generated by the first track slot (mainly the first rectangular slot and the left-side first circular slot), and from the non-uniform magnetic moment generated by the first blocking slot, causing it to move along the upper track of the track region. When the synthesized antiferromagnetic skyrmion moves to the right end of the track region, due to the symmetrical structure of the right and left ends of the track region, it will be input A' under the repulsive effect of the non-uniform magnetic moment. Therefore, the output is C'·A'·B'=0·1·0.

[0096] In one embodiment, when input A is logic '0', input B is '1', and the control bit is '0'; that is, input C·A·B = 0·0·1. The trajectory of the synthesized antiferromagnetically coupled skyrmion during the logic operation is as follows: Figure 4 As shown. Thus, the synthesized antiferromagnetic skyrmion corresponding to input B, within the second sub-region corresponding to the second control region, experiences a repulsive effect from the non-uniform magnetic moment generated by the edge of the first guide slot (mainly the second rectangular slot and the lower third rectangular slot), causing the synthesized antiferromagnetic skyrmion to move obliquely downwards (i.e., towards the lower track of the track region). Furthermore, when the synthesized antiferromagnetic skyrmion corresponding to input B reaches the position of the second track slot, it experiences a repulsive effect from the non-uniform magnetic moment generated by the second track slot (mainly the first rectangular slot and the left-side first circular slot), as well as a combined repulsive effect from the non-uniform magnetic moment generated by the second blocking slot, causing the synthesized antiferromagnetic skyrmion to move along the lower track of the track region. When the synthesized antiferromagnetic skyrmion moves to the right end of the track region, due to the symmetrical structure of the right and left ends of the track region, the synthesized antiferromagnetic skyrmion will be input B' under the repulsive effect of the non-uniform magnetic moment. Therefore, the output is C'·A'·B'=0·0·1.

[0097] In one embodiment, when input A is logic '1', input B is '1', and the control bit is '0'; that is, input C·A·B = 0·1·1. The trajectory of the synthesized antiferromagnetically coupled skyrmion during the logic operation is as follows: Figure 5 As shown. The target bits A and B are completely independent, and the output can be C'·A'·B'=0·1·1. The process is similar to the above embodiment, and will not be repeated here to avoid repetition.

[0098] In one embodiment, when input A is logic '0', input B is '0', and the control bit is '1'; that is, input C·A·B = 1·0·0. The trajectory of the synthesized antiferromagnetically coupled skyrmion during the logic operation is as follows: Figure 6 As shown. Thus, the control bit is located in the first sub-region, which is situated at the four vertices of the rectangular track area. Since the magnetic anisotropy of the first sub-region is lower than that of the surrounding areas, the synthesized antiferromagnetic skyrmion only moves within the first sub-region, from the control bit input C to the control bit output C'. Furthermore, the synthesized antiferromagnetic coupled skyrmion can be detected in the output regions of all four first sub-regions, resulting in an output C' = 1. Therefore, the output C'·A'·B' = 1·0·0.

[0099] In one embodiment, when input A is logic '1', input B is '0', and the control bit is '1'; that is, input C·A·B = 1·1·0. The trajectory of the synthesized antiferromagnetically coupled skyrmion during the logic operation is as follows: Figure 7 As shown. Thus, the synthetic antiferromagnetic coupled skyrmion corresponding to input A in the second sub-region corresponding to the first control region is repelled by the non-uniform magnetic moment generated by the edge of the first guide slot (mainly the second rectangular slot and the upper third rectangular slot), causing the synthetic antiferromagnetic coupled skyrmion to move obliquely upwards (i.e., towards the upper track of the track region). However, the synthetic antiferromagnetic coupled skyrmion corresponding to input C in the first control region is larger than the synthetic antiferromagnetic coupled skyrmion corresponding to input A, and has a faster speed under the same spin current drive. Therefore, the synthetic antiferromagnetic coupled skyrmion at the control position waits for the synthetic antiferromagnetic coupled skyrmion of input A to approach at the low anisotropy output end (i.e., output C' position). After the synthetic antiferromagnetic coupled skyrmion of input A reaches the output C' position, the two synthetic antiferromagnetic coupled skyrmions repel each other, causing the synthetic antiferromagnetic coupled skyrmion corresponding to input A to... The skyrmion changes its trajectory to move diagonally downwards (i.e., towards the middle track of the track area). Furthermore, during its continued movement, when the synthetic antiferromagnetic skyrmion corresponding to input A reaches the first track slot, it is repelled by the non-uniform magnetic moment generated by the first track slot (mainly the first circular slot and the first trapezoidal slot on the left side of the first track slot), and by the combined repulsive force of the non-uniform magnetic moment generated by the edge of the first guide slot (mainly the second trapezoidal slot). This guides the synthetic antiferromagnetic skyrmion corresponding to input A closer to the second track slot, moving along the middle track of the track area until it is slightly below the middle of the second guide slot. Finally, under the combined action of the non-uniform magnetic moment at the edge of the second guide slot and the third guide slot in the fourth control area, it is guided into output B', achieving output B' as logic '1'. Furthermore, since the magnetic anisotropy of the first sub-region is lower than that of the surrounding regions, the synthesized antiferromagnetic coupled skyrmion corresponding to input C in the first and second control regions eventually stops at output C', resulting in output C' = 1; while the synthesized antiferromagnetic coupled skyrmion corresponding to input C in the third and fourth control regions does not move. Therefore, the output C'·A'·B' = 1·0·1.

[0100] In one embodiment, when input A is logic '0', input B is '1', and the control bit is '1'; that is, input C·A·B = 1·0·1. The trajectory of the synthesized antiferromagnetically coupled skyrmion during the logic operation is as follows: Figure 8 As shown. In this way, C'·A'·B'=1·1·0 can be output. The process is similar to the above embodiment, and will not be described again here to avoid repetition.

[0101] In one embodiment, when input A is logic '1', input B is '1', and the control bit is '1'; that is, input C·A·B = 1·1·1. The trajectory of the synthesized antiferromagnetically coupled skyrmion during the logic operation is as follows: Figure 9 As shown. Thus, the synthesized antiferromagnetic skyrmion corresponding to input A in the second sub-region corresponding to the first control region is repelled by the non-uniform magnetic moment generated by the edge of the first guide slot (mainly the second rectangular slot and the upper third rectangular slot), causing the synthesized antiferromagnetic skyrmion to move obliquely upwards (i.e., towards the upper orbit of the orbit region); however, the synthesized antiferromagnetic skyrmion corresponding to input C is larger than that corresponding to input A, and has a faster speed under the same spin current drive. Therefore, the synthesis of the control position... At the low anisotropy output end (i.e., output C' position), the antiferromagnetic coupled skyrmion waits for the synthetic antiferromagnetic coupled skyrmion of input A to approach. After the synthetic antiferromagnetic coupled skyrmion of input A reaches the output C' position, the two synthetic antiferromagnetic coupled skyrmions repel each other, causing the synthetic antiferromagnetic coupled skyrmion corresponding to input A to change its trajectory and move in a downward direction (i.e. towards the middle track of the track area). Furthermore, under the repulsive force of the non-uniform magnetic moment at the edge of the circular slot on the left side of the first track slot, the synthetic antiferromagnetic coupled skyrmion is guided into the middle track.

[0102] Meanwhile, the synthetic antiferromagnetic coupled skyrmion corresponding to input B in the second sub-region corresponding to the second control region is repelled by the non-uniform magnetic moment generated by the edge of the first guide slot (mainly the second rectangular slot and the lower third rectangular slot), causing the synthetic antiferromagnetic coupled skyrmion to move obliquely downward (i.e., towards the lower orbit of the orbit region). However, the synthetic antiferromagnetic coupled skyrmion corresponding to input C in the second control region is larger than that corresponding to input B and has a faster speed under the same spin current drive. Therefore, the synthetic antiferromagnetic coupled skyrmion at the control position... The synthesized antiferromagnetic skyrmion of input B waits at the low anisotropy output end (i.e., output C' position) for the input B to approach. After the synthesized antiferromagnetic skyrmion of input B reaches the output B' position, the two synthesized antiferromagnetic skyrmions repel each other, causing the synthesized antiferromagnetic skyrmion corresponding to input B to change its trajectory and move in an upward direction (i.e. towards the middle track of the track region). Furthermore, during the continued movement, the synthesized antiferromagnetic skyrmion corresponding to input A moves to the first track slot position and meets the synthesized antiferromagnetic skyrmion corresponding to input B moving to the second track slot position, i.e., both are located in the middle track of the track region. At this point, the two synthesized antiferromagnetic coupled skyrmions corresponding to inputs A and B repel each other as they move forward along the middle track. The combined repulsive force of the non-uniform magnetic moments generated by the first and second track slots guides the synthesized antiferromagnetic coupled skyrmion corresponding to input A to move along the middle track of the track region. Upon approaching the second guide slot, the repulsive force of the non-uniform magnetic moments at the edges of the second guide slot and the corresponding third guide slot within the control region guides the synthesized antiferromagnetic coupled skyrmion corresponding to input A into output A', achieving logic '1', and guides the synthesized antiferromagnetic coupled skyrmion corresponding to input B into output B', achieving logic '1'. Therefore, the output C'·A'·B' = 1·1·1.

[0103] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0104] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

Claims

1. A Fredkin door, characterized in that, In the planar structure of the Fredkin door, the Fredkin door includes a track area, a first control area, a second control area, a third control area, and a fourth control area. The first control area and the second control area serve as input terminals located on the first side of the track area, and the third control area and the fourth control area serve as output terminals located on the second side of the track area. The first control area and the second control area are symmetrically arranged, and the first side of the track area is symmetrically arranged with respect to the second side of the track area. The first control region, the second control region, the third control region, and the fourth control region each include a first sub-region and a second sub-region, and the magnetic anisotropy constant of the first sub-region is lower than that of the second sub-region. The first sub-region is located outside the corresponding control region. Both the control bit input C and the control bit output C' are located in the first sub-region, with the control bit output C' being closer to the track region. The target bit input A is located in the second sub-region of the first control region, the target bit output A' is located in the second sub-region of the third control region, the target bit input B is located in the second sub-region of the second control region, and the target bit output B' is located in the second sub-region of the fourth control region. The target bit input A and the target bit input B are connected to the target bit output A' and the target bit output B' through the track region.

2. The Fredkin door according to claim 1, characterized in that, The track area includes an upper track, a middle track, and a lower track. The middle track is located between the upper track and the lower track. A first track groove is provided between the upper track and the middle track, and a second track groove is provided between the middle track and the lower track. In the thickness direction of the Fredkin door, the first track groove and the second track groove penetrate the composite structure layer of the Fredkin door.

3. The Fredkin door according to claim 2, characterized in that, The first track groove and the second track groove have the same structure and are arranged symmetrically; The first track groove includes a first rectangular groove, a first circular groove and a first trapezoidal groove. The first rectangular groove has a first circular groove at each end and a first trapezoidal groove at the middle position.

4. The Fredkin door according to claim 2, characterized in that, A first barrier groove is provided on the side of the track area near the first track groove, and a second barrier groove is provided on the side of the track area near the second track groove. The upper track is located between the first barrier groove and the first track groove, and the lower track is located between the second barrier groove and the second track groove. The first barrier groove and the second barrier groove penetrate the composite structure layer of the Fredkin door.

5. The Fredkin door according to claim 1, characterized in that, A first guide groove is provided between the first control area and the second control area, and a second guide groove is provided between the third control area and the fourth control area. The first guide groove is used to guide the synthetic antiferromagnetic coupled skyrmion corresponding to the target position input A and / or the target position input B into the track area. The second guide groove is used to export the synthetic antiferromagnetic coupled skyrmion to the target position output A' and / or the target position output B'. The first guide groove and the second guide groove penetrate the composite structure layer of the Fredkin gate.

6. The Fredkin door according to claim 5, characterized in that, The first guide groove and the second guide groove have the same structure and are symmetrically arranged; The first guide groove includes a second rectangular groove, a second trapezoidal groove, and a third rectangular groove. The second rectangular groove is connected to the second trapezoidal groove, and the short side of the second trapezoidal groove is close to the side of the track area. A third rectangular groove is respectively provided at the long side position of the second trapezoidal groove, at the second sub-region position close to the first control area, and at the second sub-region position close to the second control area. The second rectangular groove, the second trapezoidal groove, and the third rectangular groove of the first guide groove are used to guide the synthesized antiferromagnetic coupled skyrmions to different tracks in the track area.

7. The Fredkin door according to claim 1, characterized in that, The first control area, the second control area, the third control area and the fourth control area are all provided with a third guide groove. The third guide groove is located between the first sub-area and the second sub-area of ​​the corresponding control area, and the third guide groove penetrates the composite structure layer of the Fredkin door.

8. The Fredkin door according to claim 1, characterized in that, Each of the first sub-regions is provided with a third barrier groove, which is close to the track area and is positioned opposite to the location of the control output C'.

9. The Fredkin gate according to any one of claims 1 to 8, characterized in that, In the thickness direction of the Fredkin door, the Fredkin door includes: a composite structure layer and a heavy metal layer. The composite structure layer includes a first ferromagnetic layer, a non-magnetic layer and a second ferromagnetic layer stacked sequentially. The heavy metal layer is disposed on the composite structure layer on the side close to the first ferromagnetic layer. The magnetization direction of the first ferromagnetic layer is opposite to that of the second ferromagnetic layer, and both are perpendicular to the non-magnetic layer. Synthetic antiferromagnetic coupled skyrmions are generated in the composite structure layer. These synthetic antiferromagnetic coupled skyrmions are generated by injecting spin-polarized current into the composite structure layer.

10. A method for controlling a Fredkin gate, characterized in that, Applied to the Fredkin gate as described in any one of claims 1 to 9, the method comprises: A synthetic antiferromagnetic coupled skyrmion is generated at the input of the Fredkin gate, and the presence or absence of the synthetic antiferromagnetic coupled skyrmion is detected at the input to obtain the logic input; A driving current in a first direction is injected into the heavy metal layer of the Fredkin gate. The driving current in the first direction injects a spin current into the first ferromagnetic layer through the spin Hall effect, generating a spin-transfer torque on the magnetic moment. The synthesized antiferromagnetic coupled skyrmion moves from the input end to the output end of the Fredkin gate through the orbital region. The movement range of the synthesized antiferromagnetic coupled skyrmion corresponding to the control bit input C is located within the first sub-region. The presence or absence of the synthesized antiferromagnetic coupled skyrmion is detected at the output terminal to obtain the logic output corresponding to the logic input.

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