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arXiv · 2602.12440

Magnetotransport Spectroscopy of Strongly Rashba-Split Hole Subbands Reveals Many-Body Interactions

F. Sfigakis·N. A. Cockton·M. Korkusinski·S. R. Harrigan·G. Nichols·Z. D. Merino·T. Zou·A. C. Coschizza·T. Joshi·A. Shetty·M. C. Tam·Z. R. Wasilewski·S. A. Studenikin·D. G. Austing·J. B. Kycia·J. Baugh
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Abstract

We report the results of magnetotransport experiments carried out on low-disorder 2D hole gases (2DHG) in the strongly correlated liquid regime, hosted in dopant-free (100) GaAs/AlGaAs single heterojunctions. Over a wide range of 2DHG densities (from 0.7 $\times$ 10$^{15}$/m$^2$ to $2 \times 10^{15}$/m$^2$), Fourier analysis of low-field (B < 1 T) Shubnikov-de Haas oscillations reveals two spin-orbit-split heavy-hole (HH) subbands with distinct effective masses contributing to transport. Surprisingly, the lighter-mass HH subband exhibits a parabolic dispersion with Fermi wavevector below the anticrossing between the heavy-hole and light-hole subbands, while the heavier HH subband is non-parabolic throughout. Quantitative comparison with numerical calculations based on the Luttinger model reveals that both effective masses are enhanced by a common factor ($\approx$ 2.3), which we attribute to many-body interactions. This common scaling factor has a very weak dependence on the 2DHG density, likely due to band hybridization. Our measured hole masses are compared with published cyclotron resonance and magnetotransport values. We propose a cohesive framework reconciling the long-standing three-way discrepancy between Luttinger theory, magnetotransport, and cyclotron resonance measurements of density-dependent effective masses in partially spin-orbit-polarized heavy-hole systems in GaAs.

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F. Sfigakis, N. A. Cockton, M. Korkusinski, S. R. Harrigan, G. Nichols, Z. D. Merino, T. Zou, A. C. Coschizza, T. Joshi, A. Shetty, M. C. Tam, Z. R. Wasilewski, S. A. Studenikin, D. G. Austing, J. B. Kycia, J. Baugh. 2026-02-12. Magnetotransport Spectroscopy of Strongly Rashba-Split Hole Subbands Reveals Many-Body Interactions. https://arxiv.org/abs/2602.12440

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