Spin transistors based on voltage-controlled magnetic resonators in multiferroic antiferromagnets

Abstract

Provided are voltage-controlled spin field effect transistors ("spin transistors") and methods of their use in switching applications. In the spin transistors, a spin current is transmitted from a spin injection contact to a spin detection contact via magnons through a multiferroic antiferromagnetic channel. The spin current transmission is modulated by applying a gate voltage that increases the number of domain boundaries of the multiferroic antiferromagnetic material.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. nonprovisional patent application No. 16 / 809,970, filed March 5, 2020, the entire contents of which are incorporated herein by reference. Background Technology

[0003] Spin field-effect transistors regulate the spin current delivered from the spin injector to the spin detector via a spin channel that propagates the spin current through a magnon. Thus, a spin field-effect transistor can be considered a spintronic analog of a conventional field-effect transistor. Spin field-effect transistors offer several advantages over conventional transistors, including lower power consumption, faster switching speeds, and non-volatility.

[0004] Since Das and Datta proposed the first spin field-effect transistor (SFET), several SFET designs have been proposed (S. Datta, B. Das, et al., Appl. Phys. Lett. 56 665 (1990)). These include recent examples of SFETs that use ferromagnetic or antiferromagnetic insulators as spin channel materials (Lebrun, R., et al., “Tunable long-distance spin transport in a crystalline antiferromagnetic ironoxide” Nature 561. 7722 (2018): 222-225). In these transistors, the magnon transport in the channel is controlled by a large magnetic field, which makes it difficult to scale the transistor down to practical dimensions. Summary of the Invention

[0005] A voltage-controlled spin transistor and a method for operating the spin transistor are provided.

[0006] One embodiment of a voltage-controlled spin transistor includes: a spin injector contact; a spin detector contact; a multiferroic material layer forming a channel between the spin injector contact and the spin detector contact; at least one top gate contact; and at least one bottom gate contact, wherein the at least one top gate contact and the at least one bottom gate contact are configured to apply a gate voltage across the channel.

[0007] One embodiment of a method for operating a spin transistor of the type described herein includes the steps of: generating a spin current in a spin injector contact, thereby injecting the spin current into a channel and propagating it through the channel to a spin detector contact via a magnon; and applying a gate voltage across the channel, wherein the application of the gate voltage increases the density of domain boundaries in the channel and attenuates the spin current propagation through the channel. The spin transistor can then be switched back to its high spin current propagation state by applying a negative voltage across the channel.

[0008] Other key features and advantages of the invention will become apparent to those skilled in the art upon reading the following drawings, detailed description and appended claims. Attached Figure Description

[0009] Illustrative embodiments of the present invention will now be described with reference to the accompanying drawings, wherein the same reference numerals denote the same elements.

[0010] Figure 1 This is a schematic diagram of a voltage-controlled spin transistor in the on state (top diagram) and the off state (bottom diagram).

[0011] Figure 2 This is a schematic diagram of a voltage-controlled spin transistor, showing magnetoresistive transmission through a multiferroic antiferromagnetic channel (back gate contact not shown).

[0012] Figure 3A : Reciprocal space diagram showing the (103) diffraction peaks of the STO substrate, SRO buffer layer and BFO film. Figure 3B and Figure 3C Out-of-plane dimensions of a 600nm thick BFO film Figure 3B ) and in the plane ( Figure 3C Piezoelectric microscopy image, where the leftmost portion of the scanned area is in a native (as-grown) domain state, and the remaining area has switched to an upward state. Domain walls exist between the two domains. The in-plane components of the two domains are the same.

[0013] Figure 4A and Figure 4B

[110] BFO (001) film on staggered STO (001) ( Figure 4A ) and TSO(011) o BFO(111) thin film on Figure 4B The NXMS images of the films are shown. Both images show two peaks, one in each direction along a single propagation vector, demonstrating the single-domain properties of both films.

[0014] Figure 5A This is a schematic diagram of the NiFe / BiFeO3 / SrRuO3 three-layer structure.

[0015] Figure 5B It was shown as Figure 5A The effective spin torque ratio is a function of the thickness of the BiFeO3 layer in the three-layer structure. Detailed Implementation

[0016] A spin field-effect transistor is provided. In a spin transistor, spin current transport through a multiferroic antiferromagnetic channel is controlled by the application of a gate voltage, which alters the domain structure of the channel and attenuates spin current transport. Using voltage instead of a strong magnetic field to modulate the spin current makes the transistor efficient, scalable, and easy to integrate with existing integrated circuit manufacturing processes.

[0017] An embodiment of a voltage-controlled spin field-effect transistor (also simply a spin transistor) is schematically shown in Figure 1 As shown in the diagram, the spin transistor includes a spin injector contact 102, a spin detector contact 104, and a channel 106 providing a path for spin current to transfer from the spin injector contact 102 to the spin detector contact 104. The transistor also includes a top gate contact 108 and a bottom gate contact 110, which are configured to apply a gate voltage across the channel 106 (i.e., through the thickness of the channel 106). The top gate contact and the bottom gate contact are configured to apply a gate voltage across the channel 106 provided that they are positioned relative to the channel and to each other in a manner that allows voltage to be applied across the channel. For illustration, the top gate contact 108 and the bottom gate contact 110 may be positioned on the top and bottom surfaces of the channel 106, respectively, as shown in the diagram. Figure 1 As shown in the diagram. Spin transistors typically also include a substrate 112. Figure 1 In the spin transistor, a single top gate contact and a single bottom gate contact are used. However, in other embodiments, multiple top gate contacts may be used in conjunction with a single bottom gate contact or multiple bottom gate contacts.

[0018] In the voltage-controlled spin transistor described herein, the channel is provided by a multiferroic material layer having both antiferromagnetic and ferroelectric order. In the initial “on” state, the multiferroic material of the channel has a low domain density, and more preferably, is a mono-domain multiferroic material having a single polarization domain (indicated by a downward arrow). As used herein, the term “mono-domain multiferroic” refers to a multiferroic material having a uniform Néel vector (one antiferromagnetic domain) and a polarization vector (one ferroelectric domain). Because it is difficult to grow a multiferroic material layer that is entirely mono-domain, for the purposes of this disclosure, the material can be considered a mono-domain material if at least 95%, more preferably at least 98% or at least 99% of the multiferroic material is in a single ferroelastic, ferroelectric, and magnetic domain.

[0019] like Figure 1As shown in the figure above, in the single-domain state, the polarization of the material is oriented in the same direction throughout the channel, and the material has essentially a single magnetic domain with a single cycloidal magnetic polarity. In this initial state, due to the low density or complete absence of domain boundaries, the spin current injected into the channel from the spin injector contact can propagate through the magnon via the multiferroic material to the spin detector contact. When a gate voltage is applied across the channel, the polarization of the multiferroic material subjected to the gate voltage 118 in the channel region is switched, and the magnetic polarity is also switched due to the magnetoelectric coupling between the ferroelectric order and antiferromagnetic order in the multiferroic material. Figure 1 As shown in the figure below, this ferroelectric switching creates a region in the channel between the top and bottom gate contacts where polarization is switched and new domain boundaries are formed. Therefore, the application of the gate voltage increases the density of domain boundaries in the channel, which leads to a decrease in the spin current transport through the channel. If the multiferroic material was initially a single-domain material, then the ferroelectric switching transforms the single-domain multiferroic material into a multi-domain multiferroic material. The decrease in spin current switches the spin transistor from an "on" state to an "off" state.

[0020] Not intended to be limited to any particular theory of the invention, the inventors believe that attenuation in spin current transport can be attributed at least in part to spin current scattering at domain boundaries formed within the channel due to ferroelectric order switching. In some embodiments of the spin transistor, a greater number of domain boundaries can be generated by using multiple (i.e., two or more) gates distributed along the length of the transistor channel.

[0021] Bismuth ferrite, BiFeO3 (“BFO”), is an example of a multiferroic antiferromagnetic material that can be used as a channel in a voltage-controlled spin transistor. Using BFO is advantageous because it is multiferroic at room temperature (e.g., in a temperature range from about 22°C to about 25°C) and because it can be grown as a low-domain-density or single-domain material. BFO can be doped or undoped. For example, BFO can be doped with lanthanum or other dopant atoms to tune the gate voltage required to switch its polarization. It is conceivable that other multiferroic materials could be used. However, their use is generally less practical because these typically require operation at very low temperatures.

[0022] Single-domain BFO films can be epitaxially grown, as described in the following literature: Baek, SH et al., “Ferroelastic switching for nanoscale non-volatile magnetoelectric devices” Nature Materials 9.4 (2010):309-314; Saenrang, Wittawat et al., “Deterministic and robust room-temperature exchange coupling in monodomain multiferroic BiFeO3 heterostructures” Nature Communications 8.1 (2017):1-8; Price, N. Waterfield et al., “Strain Engineering a Multiferroic Monodomain in Thin-Film BiFeO3” Physical Review Applied 11.2 (2019):024035; and Kuo, CY et al., “Single-domain multiferroic BiFeO3 films” Nature Communications 7.1 (2016):1-7. The properties of single-domain (also known as monodomain) BFOs and a detailed description of the epitaxial growth processes that can be used to form single-domain BFO layers can be found in these references and Example 1 below. In short, strained single-domain (001) exhibits both ferroelectric and antiferromagnetic single-domain properties. pc Oriented BFO films can be grown via epitaxial growth on a SrTiO3 (STO) single-crystal substrate having an oriented

[110] pc The (001)BFO film is 4° off-cut and a thin SrRuO3 (SRO) layer is deposited on it. The SRO layer can be deposited on the growth substrate before BFO growth. When an external electric field is applied, the electronic polarization of the (001)BFO film undergoes a 71° reversal.

[0023] Single domain (111) possessing ferroelectric and antiferromagnetic single-domain properties pc The BFO film can be grown epitaxially on an NdGaO3 (NGO) substrate or a TbScO3 (TSO) substrate, or by depositing a thin SRO layer thereon (011). o ((111) pcThe orientation of the mirror (subscript "o" indicates Pnma orthogonal setting) is notable. In addition to promoting single-domain growth, the SRO layer can also be used as the bottom gate contact in a spin transistor incorporating a single-domain BFO as a spin current channel. When an external electric field is applied, the electronic polarization of the (111)BFO film undergoes a 180° reversal.

[0024] The length of channel 106 will depend at least in part on the distance the multiferroic material can carry spin current, and also on the desired transistor performance characteristics. A smaller channel length may be preferred if a small transistor footprint and high transistor density are desired. However, a longer channel may be preferred if maximizing the device's on / off ratio is important. For illustration, various embodiments of spin transistors have channel lengths ranging from 10 nm to 10 μm, including those ranging from 50 nm to 10 μm. However, the spin transistors described herein are not limited to spin transistors with channel lengths within this range. Channel thickness can range, for example, from 100 nm to 200 nm. The spin transistors described herein are not limited to spin transistors with channel lengths within this range, but channel 106 should be thick enough to avoid or minimize leakage current.

[0025] The spin injector contact 102 and the spin detector contact 104 comprise materials in which spin currents can be generated via the spin Hall effect or the Rashba-Edelstein effect. Therefore, suitable materials for the spin injector contact 102 and the spin detector contact include those with strong spin-orbit coupling. Such materials include heavy metals, two-dimensional electron gases (2DEGs), 4d / 5d transition metal oxides, and topological insulators. Specific examples of such materials include metals such as platinum (Pt), tantalum (Ta), tungsten (W), etc. For example, as... Figure 2 As shown, a spin current can be generated in spin injector contact 202 by passing current through the spin injector contact to generate a transverse spin current via the spin Hall effect. Therefore, spin 203 is established at the interface between spin injector contact 202 and channel 206, and the spin current is injected into channel 206. The spin injected at the interface carries net angular momentum and excites magnon 205 (indicated by the gray arrow), which propagates along the length of channel 206 to spin detector contact 204, where the spin current is absorbed and can be detected by the inverse spin Hall effect or the inverse Rashba-Edelstein effect. Thus, in a spin transistor, a multiferroic material provides the magnon transport path. The magnon transport along channel 206 is modulated using top gate contact 208 and bottom gate contact (not shown).

[0026] There are no particular restrictions on the dimensions of spin injector contacts and spin detector contacts, but these contacts can be made thin to allow for proportional scaling of the transistor. For example, spin injector contacts and spin detector contacts with thicknesses ranging from 3 nm to 10 nm and / or lengths ranging from 100 nm to 300 nm can be used. However, spin injector contacts and spin detector contacts with dimensions outside these ranges can also be used.

[0027] The top and bottom gate contacts comprise conductive materials. Typically, the top gate contact will be a metal, such as copper, gold, silver, etc. (metals include metal alloys as used herein); however, conductive non-metallic materials may also be used. As described above, a conductive film (e.g., SRO) deposited on the growth substrate prior to the epitaxial growth of the multiferroic material can be used as the bottom gate electrode, which will typically be grounded. Other conductive perovskite oxides can be used as gate contacts, including LaSrMO3. A voltage source (not shown) is connected across the top and bottom gate contacts to apply an external electric field across the channel, thereby providing voltage control for the magnon transmission through the multiferroic channel, as described above. Typical non-limiting examples of gate contact thickness include those ranging from 5 nm to 20 nm. The top gate contact can be almost as long as the channel, but electrical connections to spin injection and spin detection contacts should be avoided.

[0028] Example

[0029] Example 1 This example illustrates how single-domain BFOs can be grown and characterized.

[0030] BFO is a well-known multiferroic material that exhibits ferroelectricity (FE), ferroelasticity, and antiferromagnetism (AFM) at room temperature, with the ferroelectricity extending to T. C ~1100K and antiferromagnetic extension to T N~640K. Structurally, BFO retains a rhombohedral (R3C) structure, employing a perovskite structure with bismuth atoms at the corners of the unit cell and iron atoms at the body-center position, enclosed by octahedrons of oxygen atoms. Electrically, BFO is polar, exhibiting polarity due to the twisting of the rhombohedrons. <111> One end of the axis carries a positive charge, and the directly opposite end carries a negative charge. The BFO structure allows for four unique ferroelastic deformations, each with a different set of opposite directions. <111> Structural deformation along the direction. For each ferroelastic variant, there is a polarization orientation along the + <111> Direction or along - <111> Two unique ferroelastic variants in the direction. Furthermore, each of the eight unique combinations of one of the four ferroelastic domains and one of the two ferroelectric domains possesses three possible antiferromagnetic domains. Each AFM domain is defined by a spin cycloidal structure with a wavelength of 64 nm, whose respective propagation vector directions are 120 degrees apart and located in the {111} plane.

[0031] Domain engineering of single-domain BFO films. When BFO is grown as an epitaxial film, the domain structure is affected by the material grown on it. Substrate symmetry and orientation can be used to manipulate the ferroelastic and antiferromagnetic domain groups of the BFO film, and adding a polar buffer layer can confine the entire film to a single ferroelectric domain (where the polarization vector points towards or away from the buffer layer).

[0032] Typically, BFO films grown on single-crystal SrTiO3 (STO) substrates have equal groups for each ferroelastic domain. For (001) orthogonal BFO ​​film systems, starting with a substrate whose surface is intentionally offset at a certain angle to the precise (001) surface, the domain groups of the four ferroelastic domains can be affected. Domains polarized toward the edge of the offset step are preferred over other domain orientations to minimize strain in the film. When offset in the

[100] direction, energy-advantageous domains are cut in half. When offset in the

[110] direction, ±

[111] polarized domains are most preferred.

[0033] Since each ferroelastic domain variant will have a unique structural deformation in reciprocal space, these results can be confirmed by X-ray diffraction. Figure 3A In addition to confirming individual peaks in the reciprocal space mapping (RSM) of thin films, piezoelectric microscopy (PFM) can also map domains on the film surface. A voltage applied to the scanning tip changes the size of the domains; since BFO is piezoelectric, this causes the tip to deflect (…). Figure 3B and 3C ).

[0034] To probe the magnetic domain structure of the BFO, non-resonant X-ray magnetic scattering (NXMS) measurements were performed using synchrotron radiation (because X-ray magnetic interactions are 10 times weaker than electron interactions). -6These measurements confirm the existence of a single AFM domain in the film, because the propagation vector located in the plane is energyier than the other two propagation vectors located outside the plane. Figure 4A ).

[0035] For the (111) orthogonal BFO ​​system, staggered shearing is not required. The ferroelastic / ferroelectric combination with a polarization direction pointing directly downwards towards the film is energy superior to all other combinations. This is confirmed again using results from RSM and PFM. However, when grown on cubic STO (111), all three AFM domains are permitted. On substrates with lower symmetry than STO (111), such as orthogonal TSO or NGO (011), [further details are needed]. o The growth of BFO(111) films on the surface breaks the symmetry and is selected for use in a single AFM domain. Figure 4B The ferroelectric switching of the BFO changes the chirality of the spinocycloid from left-handed to right-handed.

[0036] Example 2 This example demonstrates the spin transport capability of single-domain BiFeO3, making it well-suited for use as a spin channel in spin transistors.

[0037] A transverse NiFe / BiFeO3 / SrRuO3 three-layer structure was grown on a DyScO3 substrate with an orientation of (110). Figure 5A This demonstrates spin transport in an insulating BiFeO3 thin film. In these types of orthogonal substrates, strain induces a striped ferroelectric domain structure in BiFeO3 with two polarization variants. The operation of the three-layer device can be understood as the bottom SrRuO3 layer acting as a spin injector, generating a transverse spin current, and the top NiFe layer acting as a spin detector, sensing how much of the generated spin current is diffused through the BiFeO3. More specifically, due to the strong spin Hall effect in SrRuO3, the longitudinal charge current J flowing in SrRuO3... c (In-plane direction) This results in a transverse spin current carrying spin angular momentum and spin accumulation at the BiFeO3 / SrRuO3 interface. When this spin angular momentum is transferred into BiFeO3, the magnon causes the spin current to diffuse through BiFeO3 to the NiFe / BiFeO3 interface. The spin current absorbed by NiFe exerts a spin torque on the NiFe magnetization. The spin current J through the BiFeO3 channel (and the NiFe / BiFeO3 interface) is estimated by measuring the charge of NiFe. d The extent of diffusion, and J d and J cThe ratio between the three layers is defined as the effective spin torque ratio in the three layers. This ratio parameterizes the efficiency of spin torque absorption in NiFe from the spin Hall source SrRuO3. The spin diffusion length of the insulating BiFeO3 is then determined by the decay of the effective spin torque ratio. Here, the effective spin torque ratio in the three layers is measured using spin torque ferromagnetic resonance (ST-FMR), a standard technique for measuring the spin torque ratio in various material systems.

[0038] Figure 5B The effective spin torque ratio is shown as a function of BiFeO3 thickness from 30 nm to 70 nm (SrRuO3 and NiFe thicknesses are fixed at 15 nm and 9 nm, respectively), where the spin torque ratio is almost constant, indicating no decay of spin current within this thickness range. The slight increase in the effective spin torque ratio at 70 nm may indicate a correlation between spin transport properties and the crystallinity of the BiFeO3 film, as thicker BiFeO3 exhibits better crystallinity. These results demonstrate the long spin diffusion length in BiFeO3 films and their ability to function as magnon channels in spin transistors.

[0039] Experimental details

[0040] For BFO films with (001) orientation, use those with

[110] orientation. pc Direction (where the subscript "pc" indicates) (001) with a 4° stagger in cubic setting pc SrTiO3 single-crystal substrates were used to generate single ferroelectric and single antiferromagnetic domains in BFO. For (111) oriented BFO films, (011) with nominally no misalignment was used. o NdGaO3 single-crystal substrate. A 30 nm thick SrRuO3 bottom electrode layer was first deposited at 600 °C via 90° off-axis RF magnetron sputtering with a chamber pressure of 200 mTorr and an Ar:O2 ratio of 3:2, and then cooled to room temperature in O2 at 300 Torr. A 2-inch diameter stoichiometric target material was held at 100 W. The BFO film was grown at 740 °C via dual-gun off-axis RF magnetron sputtering with an Ar:O2 ratio of 3:1 and a chamber pressure of 400 mTorr. The BFO target contained 5% excess Bi2O3 to compensate for the volatility of bismuth. To fabricate the target, B2O3 and Fe2O3 were ball-milled together for 1 hour, dried, sieved, and then calcined at 800 °C for 4 hours. The calcined mixture was re-ground, dried, sieved, and pressed at 10 tons. Final sintering was carried out at 850 °C for 2 hours, followed by a rise to 910 °C for 8 hours.

[0041] For metal overlays (i.e., spin implantation contacts and spin detection contacts), such as NiFe and Pt, DC sputtering can be used and is typically performed in situ on the BFO layer to maintain a clean interface; otherwise, the BFO surface can be cleaned by heating, plasma cleaning, or by minimizing transfer time. Device structure patterning can be accomplished using photoresist masks and ion milling. For switching experiments to ferroelectrically switch the BFO, the device is contacted using a probe station or via wire bonding after the substrate is mounted to the chip carrier.

[0042] Equipment Principle

[0043] As discussed in Example 1, BFO is a multiferroic material with coupled ferroelectric, ferroelastic, and antiferromagnetic orders. By applying a voltage across the BFO film, not only the ferroelectric order but also the magnetic order can be altered. The engineering of a structural template on which an epitaxial BFO ​​film is grown can reduce the overall order of the film from 24 possible domain variants to only 1 when grown on a polar buffer layer, as detailed in Example 1. This example demonstrates that the magnon transport through the BFO is long enough that a spin wave generated in one part of the film can be detected in another part of the film. Because the BFO is single-domain, there is no signal attenuation due to domain walls. Since there are no domain walls in the native BFO film, adding domain walls by switching the region of the BFO channel can act as a transistor's on / off function. By switching the BFO region deployed below the metal overlay pads (i.e., the FE gate contact), the single-domain BFO channel between the spin injector and spin detector can become a mixture of upper and lower domains, each with a domain wall between them.

[0044] The term “illustrative” is used herein to mean that it is used as an example, instance, or illustration. Any aspect or design described herein as “illustrative” is not necessarily to be construed as superior to or advantageous to other aspects or designs. Furthermore, for the purposes of this disclosure, unless otherwise stated, “a” or “an” means “one or more”.

[0045] For purposes of illustration and description, the foregoing description of illustrative embodiments of the invention has been presented. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed, and modifications and variations are possible in accordance with the foregoing teachings, or may be obtained from the practice of the invention. The embodiments were chosen and described to explain the principles of the invention and as practical applications thereof, so that those skilled in the art can utilize the invention in various embodiments and make various modifications to suit a particular intended use. The scope of the invention is intended to be defined by the appended claims and their equivalents.

Claims

1. A voltage-controlled spin transistor, comprising: Spin injector contacts, including materials in which a spin current can be generated by the spin Hall effect or the Rashba-Edelstein effect when a charge current passes through; Spin detector contacts; A layer of multiferroic antiferromagnetic material forming a channel between a spin injector contact and a spin detector contact, the multiferroic antiferromagnetic material having a first density of antiferromagnetic and ferroelectric domain boundaries; At least one top gate contact; as well as At least one bottom gate contact, The at least one top gate contact and the at least one bottom gate contact are configured to apply a gate voltage across the channel.

2. The spin transistor of claim 1, wherein the multiferroic antiferromagnetic material is a single-domain multiferroic antiferromagnetic material.

3. The spin transistor of claim 1, wherein the multiferroic antiferromagnetic material is BiFeO3.

4. The spin transistor of claim 3, wherein the BiFeO3 is in the direction of [110] pc (001) on a SrTiO3 (STO) single crystal substrate with a 4° misalignment in the direction. pc BiFeO3 facing the direction.

5. The spin transistor of claim 3, wherein the BiFe03 is (111) oriented on a NdGa03 (NGO) substrate or a TbSc03 (TSO) substrate. pc BiFe03 oriented toward the substrate.

6. The spin transistor of claim 3, wherein the BiFeO3 is a single-domain multiferroic BiFeO3.

7. The spin transistor of claim 1, wherein the spin injector contact comprises a heavy metal, a two-dimensional electron gas, a 4d transition metal oxide, a 5d transition metal oxide, or a topological insulator.

8. The spin transistor of claim 1, wherein the bottom gate contact comprises conductive perovskite oxide.

9. The spin transistor of claim 6, wherein the spin injector contact comprises SrRuO3 and the top gate contact comprises metal.

10. The spin transistor of claim 9, wherein the top gate contact comprises copper, gold, or silver.

11. A method of operating a spin transistor, the spin transistor comprising: Spin injector contacts, including materials in which a spin current can be generated by the spin Hall effect or the Rashba-Edelstein effect when a charge current passes through; Spin detector contacts; A layer of multiferroic antiferromagnetic material forming a channel between a spin injector contact and a spin detector contact, the multiferroic antiferromagnetic material having a first density of antiferromagnetic and ferroelectric domain boundaries; At least one top gate contact; as well as At least one bottom gate contact, The at least one top gate contact and the at least one bottom gate contact are configured to apply a gate voltage across the channel. The method includes: A longitudinal charge current is passed through the spin injector contact, thereby generating a transverse spin current carrying spin angular momentum in the spin injector contact. The spin current is then injected into the channel, where it excites a magnon, which propagates along the channel to the spin detector contact. as well as A gate voltage is applied across the channel, which increases the density of antiferromagnetic and ferroelectric domain boundaries in the channel and attenuates the propagation of magnons along the channel.

12. The method of claim 11, wherein the multiferroic antiferromagnetic material is a single-domain multiferroic antiferromagnetic material before the gate voltage is applied.

13. The method of claim 11, wherein the multiferroic antiferromagnetic material is BiFeO3.

14. The method of claim 13, wherein the BiFe03 is (001) BiFe03 on a SrTi03 (STO) single crystal substrate having a 4° miscut towards [110] pc pc direction.​ 15. The method of claim 13, wherein the BiFe03 is (111) oriented on a NdGa03 (NGO) substrate or a TbSc03 (TSO) substrate. pc BiFe03 oriented toward.

16. The method of claim 13, wherein the BiFeO3 is a single-domain multiferroic BiFeO3.

17. The method of claim 11, wherein the spin injector contact comprises a heavy metal, a two-dimensional electron gas, a 4d transition metal oxide, a 5d transition metal oxide, or a topological insulator.

18. The method of claim 11, wherein the bottom gate contact comprises a conductive perovskite oxide.

19. The method of claim 16, wherein the spin injector contact comprises SrRuO3 and the top gate contact comprises metal.

20. The method of claim 19, wherein the top gate contact comprises copper, gold, or silver.

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