Inversion asymmetry effects in L-valley quantum wells

We report first results of the spin-orbit coupling in GaSb/AlSb L-valley quantum well heterostructures using an improved tight-binding model. A zero-field spin splitting of L-conduction band edge exceeding 10 meV is demonstrated, which is more than one order of magnitude above typical values resulting from the Dresselhaus and Rashba terms near the zone center. The main results can be reproduced in a 4×4 k·p model including band parameters and k-linear spin splittings derived from the GaSb bulk band structure together with a coupling between the two L valleys folded onto the same point of the 2D Brillouin zone. Our results provide direct insight into L-valley heterostructures, indicating a new direction for future research on spin electronics.