Anisotropic g-tensor and strong spin-orbit interaction of holes in hexagonal germanium nanowires

Abstract

Hexagonal germanium combines direct-gap optical activity with the low-nuclear-spin environment of a group-IV material, making it a candidate platform for spin qubits and spin-photon interfaces. Using a ten-band k·p model, we study the response of confined hole states in hexagonal germanium nanowires to magnetic and electric fields. We show that, by symmetry, the top valence band of the bulk crystal has a vanishing g factor in the plane perpendicular to the c axis, in analogy with the in-plane g factor of heavy holes in two-dimensional hole gases. In nanowires, confinement induces only small transverse g-tensor components, so the g tensor remains strongly anisotropic. A transverse electric field strongly reduces the nanowire band gap, providing a gate-tunable optical signature and limiting the usable field range. The same field induces a Rashba spin-orbit interaction that is markedly stronger for fields perpendicular to the c axis and depends nonlinearly on the field strength. In narrow wires at strong fields, the spin-orbit length reaches a few tens of nanometers, comparable to hole devices in cubic silicon. We identify the microscopic origin of the Rashba coupling as a second-order process mediated by a few intermediate subbands with distinct symmetry selection rules. Our results provide guidance for the design of electrically controlled hole-spin qubits in hexagonal germanium nanowires.

Growth and morphology of core-shell nanowires incorporating dissimilar hexagonal semiconductors: the case of InAs-ZnTe
Danylo Mosiiets, Susheng Tan, Sergey Frolov +3
HAL28 Sep 2026PreprintCC BY 4.0Full textCondensed matterHALarXiv
Intrinsic time resolution of a hexagonal BC404 scintillator: A Monte Carlo study of interaction geometry and optical reflectivity
C. H. Zepeda-Fernández, L. F. Rebolledo-Herrera, E. Moreno Barbosa
arXiv8 Sep 2026PreprintarXiv licenceFull textApplied physics & instrumentationarXiv
Identifiability of the three-dimensional anisotropic thermal-conductivity tensor in thermoreflectance measurements: Single-orientation limits and full-tensor recover
Dihui Wang, Heng Ban
arXiv15 Sep 2026PreprintCC BY 4.0Full textApplied physics & instrumentationarXiv
Interaction dependence of the critical correlation length amplitude ratio in anisotropic scalar lattice ϕ⁴ theory
Leonie Müller, Stefan Wessel
arXiv26 Oct 2026PreprintCC BY 4.0Full textHigh-energy & particle physics Statistical & nonlinear physicsarXiv
The dielectric tensor for a fully anisotropic regularized Kappa plasma
Rudi Gaelzer, Horst Fichtner, Dustin Lee Schröder +2
arXiv4 Nov 2026PreprintarXiv licenceFull textSolar & stellar physics Plasma physicsarXiv

Cite

BibTeX RIS

BibTeX

@misc{das2026anisotropic,
  title = {{Anisotropic g-tensor and strong spin-orbit interaction of holes in hexagonal germanium nanowires}},
  author = {Anirban Das and Baksa Kolok and Dániel Varjas and András Pályi},
  howpublished = {arXiv},
  year = {2026},
  month = nov,
  doi = {10.48550/arxiv.2611.07846},
  eprint = {2611.07846},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2611.07846},
}

RIS

TY  - UNPB
TI  - Anisotropic g-tensor and strong spin-orbit interaction of holes in hexagonal germanium nanowires
AU  - Anirban Das
AU  - Baksa Kolok
AU  - Dániel Varjas
AU  - András Pályi
PY  - 2026
DA  - 2026/11/05
PB  - arXiv
DO  - 10.48550/arxiv.2611.07846
UR  - https://arxiv.org/abs/2611.07846
AB  - Hexagonal germanium combines direct-gap optical activity with the low-nuclear-spin environment of a group-IV material, making it a candidate platform for spin qubits and spin-photon interfaces. Using a ten-band k·p model, we study the response of confined hole states in hexagonal germanium nanowires to magnetic and electric fields. We show that, by symmetry, the top valence band of the bulk crystal has a vanishing g factor in the plane perpendicular to the c axis, in analogy with the in-plane g factor of heavy holes in two-dimensional hole gases. In nanowires, confinement induces only small transverse g-tensor components, so the g tensor remains strongly anisotropic. A transverse electric field strongly reduces the nanowire band gap, providing a gate-tunable optical signature and limiting the usable field range. The same field induces a Rashba spin-orbit interaction that is markedly stronger for fields perpendicular to the c axis and depends nonlinearly on the field strength. In narrow wires at strong fields, the spin-orbit length reaches a few tens of nanometers, comparable to hole devices in cubic silicon. We identify the microscopic origin of the Rashba coupling as a second-order process mediated by a few intermediate subbands with distinct symmetry selection rules. Our results provide guidance for the design of electrically controlled hole-spin qubits in hexagonal germanium nanowires.
ER  -

Abstract

Related

Cite