Pseudospin-electric coupling for holes beyond the envelope-function approximation

We have calculated [1] the electric-dipole (pseudospin-electric) coupling between heavy and light holes in GaAs from first principles. We find a transition dipole of 0.5 debye, a significant fraction of that for the hydrogen-atom 1s→2p transition. In addition, we derive the Dresselhaus spin-orbit coupling that is generated by this transition dipole for heavy holes in a triangular quantum well. A quantitative microscopic description of this pseudospin-electric coupling may be important for understanding the origin of spin splitting in quantum wells, spin coherence/relaxation (T₂^*/T₁) times, spin-electric coupling for cavity-QED, electric-dipole spin resonance, and spin non-conserving tunneling in double quantum dot systems. Related results for the first-principles calculation of hyperfine couplings [2] for holes in GaAs, silicon, and germanium will also be discussed.

[1] P. Philippopoulos, S. Chesi, D. Culcer, and W. A. Coish, Phys. Rev. B 102, 075310 (2020).

[2] P. Philippopoulos, S. Chesi, W. A. Coish, Phys. Rev. B 101, 115302 (2020).