Interplay between many-body and spin-orbit interactions \\ in Rashba-split heavy hole effective masses

We present magnetotransport experiments 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, Fourier analysis of low-field (B < 1 T) Shubnikov–de Haas oscillations reveals two spin-orbit-split heavy-hole (HH) bands with distinct effective masses contributing to transport. The lighter-mass HH subband exhibits a parabolic dispersion with Fermi wavevector before the anticrossing between the heavy-hole and light-hole bands, while the heavier HH band is non-parabolic throughout. Quantitative comparison with numerical simulations based on the Luttinger model reveals that both effective masses are enhanced by a common factor of approximately two, likely due to electron-electron interactions. This common scaling factor does not increase as the 2DHG density decreases, likely due to the partial spin-orbit polarization. We compare our values with published cyclotron resonance masses and transport masses. We propose a cohesive framework reconciling the long-standing three-way discrepancy between Luttinger theory, magnetotransport, and cyclotron resonance measurements of effective masses in partially spin-orbit-polarized heavy-hole systems in GaAs.