|
Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Engineering / Faculty of Engineering >
Peer-reviewed Journal Articles, etc >
Spin splitting of the conduction band by exchange interaction in the valence band through a k . p interband process in ferromagnetic semiconductors
| Title: | Spin splitting of the conduction band by exchange interaction in the valence band through a k . p interband process in ferromagnetic semiconductors |
| Authors: | Hayashida, Kenji Browse this author | | Akera, Hiroshi Browse this author →KAKEN DB |
| Issue Date: | 21-Jun-2022 |
| Publisher: | American Physical Society (APS) |
| Journal Title: | Physical Review B |
| Volume: | 105 |
| Issue: | 23 |
| Start Page: | 235203 |
| Publisher DOI: | 10.1103/PhysRevB.105.235203 |
| Abstract: | The momentum-dependent spin splitting in the conduction band couples orbital motion to spin and enables electrical control of spin. Currently, this control relies on the relativistic spin-orbit interaction (SOI), which limits useful materials to those containing heavy elements. Recently, Naka et al. [Nat. Commun. 10, 4305 (2019)] have found a momentum-dependent spin splitting originating from the exchange interaction, which is expected to extend spintronic materials to those without heavy elements. In this paper, we propose a mechanism of the exchange-induced orbital-spin coupling by extending the k . p theory. As an example, we consider an n-type ferromagnetic semiconductor (nFMS) of Td point group symmetry with the p-d exchange interaction between an electron in the valence band and the spin of a magnetic ion and evaluate the spin splitting in the conduction band of P6 irreducible representation from the eight-band k . p Hamiltonian. We find that the lowest-order spin splitting in bulk is of the second order of momentum, which results in a nonzero splitting at kx = ky = 0 in a quantum well with a nonzero quantized momentum kz. An estimation shows that the p-d exchange interaction is the dominant origin of the conduction-band spin splitting in InFeAs nFMS. We also calculate the intrinsic anomalous Hall conductivity of bulk InFeAs generated by the p-d exchange, which provides both the coupling of orbital motion to spin and that of spin to nFMS magnetization. We find that the p-d exchange-induced Hall conductivity exhibits an accelerated increase with Fe density, in contrast to that produced by the s-d exchange and the Dresselhaus SOI. This finding suggests that the extended k . p mechanism of orbital-spin coupling is expected to help find remarkable phenomena and useful applications in a wide variety of materials and structures. |
| Rights: | Copyright (2022) by The American Physical Society. |
| Type: | article |
| URI: | http://hdl.handle.net/2115/86497 |
| Appears in Collections: | 工学院・工学研究院 (Graduate School of Engineering / Faculty of Engineering) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
|
Submitter: 明楽 浩史
|
