Giant spin splittings inGaSb∕AlSbL-valley quantum wells

Abstract

For $\mathrm{Ga}\mathrm{Sb}∕\mathrm{Al}\mathrm{Sb}$ heterostructures with the absolute conduction minimum deriving from the $L$ point of the bulk Brillouin zone, we predict zero-field spin splittings well exceeding $10\phantom{\rule{0.3em}{0ex}}\mathrm{meV}$, about one order of magnitude larger than typical values resulting from the Dresselhaus and Rashba spin-orbit coupling terms near the zone center. Electronic structure calculations are performed within an improved tight-binding model and the main results can be reproduced in a $4\ifmmode\times\else\texttimes\fi{}4\phantom{\rule{0.3em}{0ex}}\mathbf{k}∙\mathbf{p}$ Hamiltonian including band parameters and $k$-linear spin splittings derived from the GaSb bulk. Our results provide direct insight into $L$-valley heterostructures, indicating a promising direction for future research on spintronics.