Spinorbit interactions in inversionasymmetric twodimensional hole systems: A variational analysis
Abstract
We present an indepth study of the spinorbit (SO) interactions occurring in inversionasymmetric twodimensional hole gases at semiconductor heterointerfaces. We focus on common semiconductors such as GaAs, InAs, InSb, Ge, and Si. We develop a semianalytical variational method to quantify SO interactions, accounting for both structure inversion asymmetry (SIA) and bulk inversion asymmetry (BIA). Under certain circumstances, using the SchriefferWolff (SW) transformation, the dispersion of the ground state heavy hole subbands can be written as E (k ) =A k^{2}B k^{4}±C k^{3} where A ,B , and C are material and structuredependent coefficients. We provide a simple method of calculating the parameters A ,B , and C , yet demonstrate that the simple SW approximation leading to a SIA (Rashba) spin splitting ∝k^{3} frequently breaks down. We determine the parameter regimes at which this happens for the materials above and discuss a convenient semianalytical method to obtain the correct spin splitting, effective masses, Fermi level, and subband occupancy, together with their dependence on the charge density, and dopant type, for both inversion and accumulation layers. Our results are in good agreement with fully numerical calculations as well as with experimental findings. They suggest that a naive application of the simple cubic Rashba model is of limited use in either common heterostructures or quantum dots. Finally, we find that for the single heterojunctions studied here the magnitudes of BIA terms are always much smaller than those of SIA terms.
 Publication:

Physical Review B
 Pub Date:
 February 2017
 DOI:
 10.1103/PhysRevB.95.075305
 arXiv:
 arXiv:1604.08759
 Bibcode:
 2017PhRvB..95g5305M
 Keywords:

 Condensed Matter  Mesoscale and Nanoscale Physics
 EPrint:
 13 pages, 8 figures