Nanoscale high-performance topological inductor
An electrical device includes a current transport layer made of an anomalous Hall material. The electrical device also includes a first ferromagnetic island in physical contact with the current transport layer and a second ferromagnetic island in physical contact with the current transport layer, the second ferromagnetic island oriented with respect to the first ferromagnetic island such as to concentrate a magnetic field, generated by current flow along a conducting surface of the anomalous Hall material, over the first ferromagnetic island and the second ferromagnetic island.
1. An electrical device comprising:
a current transport layer comprising an anomalous Hall material;
a first ferromagnetic island in physical contact with the current transport layer; and
a second ferromagnetic island in physical contact with the current transport layer, the second ferromagnetic island oriented with respect to the first ferromagnetic island such as to concentrate a magnetic field, generated by current flow along a conducting surface of the anomalous Hall material, over the first ferromagnetic island and the second ferromagnetic island.
2. The electrical device of claim 1 , further comprising:
an integrated circuit on which is deposited the current transport layer; and
a voltage source connected to opposing ends of the current transport layer.
3. The electrical device of claim 1 , wherein the first ferromagnetic island has a first magnetization and the second ferromagnetic island has a second magnetization oriented opposite to the first magnetization.
4. The electrical device of claim 1 , further comprising one or more additional ferromagnetic islands coupled electrically in series with the first ferromagnetic and the second ferromagnetic island and in one of physical, electrical or magnetic contact with the current transport layer.
5. The electrical device of claim 1 , wherein the anomalous Hall material has a non-zero Chern number.
6. The electrical device of claim 1 , wherein the anomalous Hall material comprises one of: an anomalous Hall effect (AHE) material, a quantum anomalous Hall effect (QAHE) material, a topological insulator, a topological magnetic insulator, a quantum anomalous Hall (QAH) insulator, a Chern insulator, a Weyl or other topological semi-metal, a magnetic semiconductor, or a topological crystalline insulator.
7. The electrical device of claim 1 , wherein the anomalous Hall material comprises at least one of: HgTe; Bi x SB 1-x ; Sb 2 Te 3 ; Bi 2 Te 3 ; Bi 2 Se 3 ; TlBiTe 2 ; TIBiSe 2 ; GeBi 4 Te 7 ; (In, Mn)As; (Ga, Mn)As; graphene, silicene, SnTe, Pb x Sn 1-x Te, HgCr 2 Se 4 , and TaAs.
8. The electrical device of claim 1 , wherein the first ferromagnetic island has a first magnetization oriented perpendicular to the current transport layer and the second ferromagnetic island has a second magnetization oriented perpendicular to the current transport layer and opposite from the first magnetization.
9. The electrical device of claim 1 , wherein the first ferromagnetic island and the second ferromagnetic island form a first inductor, further comprising a third ferromagnetic island in physical contact with the current transport layer and aligned generally along an axis formed between the first ferromagnetic island and the second ferromagnetic island, wherein the second ferromagnetic island and the third ferromagnetic island form a second inductor in series with the first inductor.
10. One of a radio frequency filter, a radio frequency amplifier, or an electrical transformer incorporating the electrical device of claim 1 .
11. An electrical device comprising:
a first current transport layer comprising an anomalous Hall material;
a first ferromagnetic island in physical contact with the first current transport layer;
a second ferromagnetic island in physical contact with the first current transport layer and positioned such as to define a first region separating the first ferromagnetic island from the second ferromagnetic island on the first current transport layer;
a second current transport layer comprising an anomalous Hall material and electrically coupled to the first current transport layer;
a third ferromagnetic island in physical contact with the second current transport layer;
a fourth ferromagnetic island in physical contact with the second current transport layer and positioned such as to define a second region separating the third ferromagnetic island from the fourth ferromagnetic island on the second current transport layer; and
a trivial insulator positioned between the first current transport layer and the second transport layer.
12. The electrical device of claim 11 , wherein the first ferromagnetic island is oriented opposite to the third ferromagnetic island across the trivial insulator and the second ferromagnetic island is oriented opposite to the fourth ferromagnetic island across the trivial insulator.
13. The electrical device of claim 11 , further comprising:
a contact plate attached to an end of each of the first current transport layer and the second transport layer; and
a voltage source connected between a second end of each of the first current transport layer and the second transport layer.
14. The electrical device of claim 11 , wherein the first ferromagnetic island has a first magnetization and the second ferromagnetic island has a second magnetization oriented opposite to the first magnetization, and wherein the third ferromagnetic island has the first magnetization and the second ferromagnetic island has the second magnetization oriented opposite to the first magnetization.
15. The electrical device of claim 14 , wherein the first magnetization is substantially equal to the second magnetization.
16. The electrical device of claim 11 , wherein the anomalous Hall material has a non-zero Chern number.
17. The electrical device of claim 11 , wherein the anomalous Hall material comprises one of: an anomalous Hall effect (AHE) material, a quantum anomalous Hall effect (QAHE) material, a topological insulator, a topological magnetic insulator, a quantum anomalous Hall (QAH) insulator, a Chern insulator, a Weyl semi-metal, a magnetic semiconductor, or a topological crystalline insulator.
18. The electrical device of claim 11 , wherein the anomalous Hall material comprises at least one of: HgTe; Bi x SB 1-x ; Sb 2 Te 3 ; Bi 2 Te 3 ; Bi 2 Se 3 ; TIBiTe 2 ; TIBiSe 2 ; GeBi 4 Te 7 ; (In, Mn)As; (Ga, Mn)As; graphene, silicene, SnTe, Pb x Sn 1-x Te, HgCr 2 Se 4 , or TaAs.
19. The electrical device of claim 11 , wherein the first ferromagnetic island has a first magnetization oriented perpendicular to the first current transport layer and the second ferromagnetic island has a second magnetization oriented perpendicular to the first current transport layer and opposite from the first magnetization.
20. The electrical device of claim 11 , wherein the third ferromagnetic island has a first magnetization oriented perpendicular to the second current transport layer and the fourth ferromagnetic island has a second magnetization oriented perpendicular to the second current transport layer and opposite from the first magnetization.