Dependence of Spin-orbit Parameters in AlxGa1-xN/GaN Quantum Wells on the Al Composition of the Barrier

In this paper, we obtain considerable spin-orbit (SO) parameters in Al_xGa_1-xN/GaN quantum wells (QWs) with sheet carrier concentration N_s =120×10 ¹¹/cm². With increasing Al content (x) of the barrier, the SO parameters increase as a whole, and the two major contributions are found to be the decrease of the expansion region of the envelope functions and the increase of the polarized electric field in the well. Compared with the Rashba parameters for the first two subbands, the intersubband SO parameter is a bit smaller and varies more slowly with x. The results indicate the SO parameters, especially the Rashba parameters can be engineered by the Al composition of the barrier, which may be helpful to the spin manipulation of III-nitride low-dimensional heterostructures.