Spin injection source, magnetic memory, spin hall oscillator, computer, and magnetic sensor
According to one embodiment, a spin injection source comprising a half Heusler alloy-topological semi-metal that has a surface state of Dirac type and that is in contact with a ferromagnet. The half Heusler alloy-topological semi-metal supplies a spin current to the ferromagnet based on a current flowing in a direction parallel to a first surface that is in contact with the ferromagnet.
1. A spin injection source comprising
YPtBi that is a non-magnetic half Heusler alloy-topological semi-metal, has a spin Hall angle exceeding 1, has a surface state of Dirac type, and is in contact with a ferromagnet,
wherein the YPtBi supplies a spin current to the ferromagnet based on a current flowing in a direction parallel to a first surface that is in contact with the ferromagnet.
2. The spin injection source according to claim 1 , wherein the YPtBi has a (111) crystal plane.
3. The spin injection source according to claim 1 , wherein a heat resistance of the YPtBi is equal to or higher than 300° C. and equal to or lower than 600° C.
4. A magnetic memory comprising:
a spin injection source containing YPtBi that is a non-magnetic half Heusler alloy-topological semi-metal, has a spin Hall angle exceeding 1, and has a surface state of Dirac type; and
a magnetic memory element including a first ferromagnet that is in contact with the spin injection source, a second ferromagnet, and an insulator interposed between the first ferromagnet and the second ferromagnet,
wherein:
the YPtBi supplies a spin current to the first ferromagnet based on a current flowing in a direction parallel to a first surface that is in contact with the first ferromagnet, and
the first ferromagnet is magnetization-reversible by the spin current.
5. The magnetic memory according to claim 4 , wherein the current flows from the spin injection source to the second ferromagnet.
6. The magnetic memory according to claim 4 , wherein:
the YPtBi supplies to the first ferromagnet the spin current that is generated by a spin Hall effect arising from the surface state of Dirac type, and
a magnetization direction of the first ferromagnet is controlled by an anti-damping torque generated by injection of the spin current.
7. The magnetic memory according to claim 4 , wherein the first ferromagnet contains at least one of Co, Fe, Ni, Mn, B, Si, Zr, Nb, Ta, Ru, Ir, Pt, Ga, Al, Pd, Tb, and Gd.
8. The magnetic memory according to claim 4 , wherein the second ferromagnet contains at least one of Co, Fe, Ni, Mn, B, Si, Zr, Nb, Ta, Ru, Ir, Pt, Ga, Al, Pd, Tb, and Gd.
9. The magnetic memory according to claim 4 , wherein the insulator is a metal oxide that is nonmagnetic and contains at least one of Ga, Al, Mg, Hf, and Zr.
10. The magnetic memory according to claim 4 , wherein the YPtBi has a (111) crystal plane.
11. The magnetic memory according to claim 4 , wherein a heat resistance of the YPtBi is equal to or higher than 300° C. and equal to or lower than 600° C.
12. A magnetic memory comprising:
a spin injection source containing YPtBi that is a non-magnetic half Heusler alloy-topological semi-metal, has a spin Hall angle exceeding 1, and has a surface state of Dirac type;
a first ferromagnet that is in contact with the spin injection source and includes a plurality of magnetic domains, the plurality of magnetic domains including a first magnetic domain;
a first conductor that is coupled to one end of at least one of the first ferromagnet and the spin injection source;
a second conductor that is coupled to the other end of at least the one of the first ferromagnet and the spin injection source;
a third conductor that is provided between the first conductor and the second conductor and that is coupled to at least one of the first ferromagnet and the spin injection source;
a second ferromagnet that is provided between the first conductor and the third conductor; and
an insulator interposed between the first magnetic domain of the first ferromagnet and the second ferromagnet,
wherein:
in a case of controlling a magnetization direction of the first magnetic domain, the YPtBi supplies a spin current to the first magnetic domain based on a current flowing between the first conductor and the third conductor in a direction parallel to a first surface that is in contact with the first ferromagnet, and
in a case of moving the plurality of magnetic domains of the first ferromagnet, a voltage is applied across the first conductor and the second conductor.
13. The magnetic memory according to claim 12 , wherein;
the YPtBi supplies to the first ferromagnet the spin current that is generated by a spin Hall effect arising from the surface state of Dirac type, and
magnetization direction of the first ferromagnet is controlled by an anti-damping torque generated by injection of the spin current.
14. The magnetic memory according to claim 12 , wherein the first ferromagnet contains at least one of Co, Fe, Ni, Mn, B, Si, Zr, Nb, Ta, Ru, Ir, Pt, Ga, Al, Pd, Tb, and Gd.
15. The magnetic memory according to claim 12 , wherein the second ferromagnet contains at least one of Co, Fe, Ni, Mn, B, Si, Zr, Nb, Ta, Ru, Ir, Pt, Ga, Al, Pd, Tb, and Gd.
16. The magnetic memory according to claim 12 , wherein the insulator is a metal oxide that is nonmagnetic and contains at least one of Ga, Al, Mg, Hf, and Zr.
17. The magnetic memory according to claim 12 , wherein the YPtBi has a (111) crystal plane.
18. The magnetic memory according to claim 12 , wherein a heat resistance of the YPtBi is equal to or higher than 300° C. and equal to or lower than 600° C.
19. A spin Hall oscillator comprising:
a spin injection source containing YPtBi that is a non-magnetic half Heusler alloy-topological semi-metal, has a spin Hall angle exceeding 1, and has a surface state of Dirac type; and
a first ferromagnet that is in contact with the spin injection source,
wherein the first ferromagnet oscillates upon receipt of a spin current generated by a spin Hall effect of the YPtBi and injected from the spin injection source.
20. The spin Hall oscillator according to claim 19 , further comprising:
a second ferromagnet; and
an insulator interposed between the first ferromagnet and the second ferromagnet.
21. The spin Hall oscillator according to claim 20 , further comprising:
a conductor that is in contact with the second ferromagnet; and
a resistance element one end of which is coupled to the YPtBi and another end of which is coupled to the conductor.
22. The spin Hall oscillator according to claim 20 , wherein the second ferromagnet contains at least one of Co, Fe, Ni, Mn, B, Si, Zr, Nb, Ta, Ru, Ir, Pt, Ga, Al, Pd, Tb, and Gd.
23. The spin Hall oscillator according to claim 20 , wherein the insulator is a metal oxide that contains at least one of Ga, Al, Mg, Hf, and Zr.
24. The spin Hall oscillator according to claim 19 , wherein the first ferromagnet contains at least one of Co, Fe, Ni, Mn, B, Si, Zr, Nb, Ta, Ru, Ir, Pt, Ga, Al, Pd, Tb, and Gd.
25. The spin Hall oscillator according to claim 19 , wherein the YPtBi has a (111) crystal plane.
26. The spin Hall oscillator according to claim 19 , wherein a heat resistance of the YPtBi is equal to or higher than 300° C. and equal to or lower than 600° C.
27. A computer comprising an artificial neuron including a spin Hall oscillator, wherein:
the spin Hall oscillator includes:
a spin injection source containing YPtBi that is a non-magnetic half Heusler alloy-topological semi-metal, has a spin Hall angle exceeding 1, and has a surface state of Dirac type; and
a first ferromagnet that is in contact with the spin injection source, and
the first ferromagnet oscillates upon receipt of a spin current generated by a spin Hall effect of the YPtBi and injected from the spin injection source.
28. The computer according to claim 27 , wherein the YPtBi has a (111) crystal plane.
29. The computer according to claim 27 , wherein a heat resistance of the YPtBi is equal to or higher than 300° C. and equal to or lower than 600° C.
30. A magnetic sensor comprising:
a detection layer including YPtBi that is a non-magnetic half Heusler alloy-topological semi-metal, has a spin Hall angle exceeding 1, and has a surface state of Dirac type; and
a ferromagnet that is in contact with the detection layer and has a magnetization directed in an in-plane direction of a first surface that is in contact with the detection layer.
31. The magnetic sensor according to claim 30 , wherein by causing a current to flow in a direction perpendicular to the first surface in the ferromagnet, thereby injecting a spin polarized current to the YPtBi, a voltage depending on a direction of the magnetization of the ferromagnet is generated by an inverse spin Hall effect of the YPtBi.
32. The magnetic sensor according to claim 30 , wherein the ferromagnet contains at least one of Co, Fe, Ni, Mn, B, Si, Zr, Nb, Ta, Ru, Ir, Pt, Ga, Al, Pd, Tb, and Gd.
33. The magnetic sensor according to claim 30 , wherein the YPtBi has a (111) crystal plane.
34. The magnetic sensor according to claim 30 , wherein a heat resistance of the YPtBi is equal to or higher than 300° C. and equal to or lower than 600° C.