Experimental approaches to zero-field spin splitting in a gated high-mobility In_0.53Ga_0.47 As/InP quantum well structure: Weak antilocalization and beating pattern

We report on the strong spin-orbit (SO) interaction in a gated high-mobility In_0.53Ga_0.47 As/InP quantum well two-dimensional electron gas. We establish that the SO interaction is dominated by the Rashba mechanism. The Rashba coupling parameters determined from analysis of both weak antilocalization and the beating pattern in the Shubnikov-de Haas oscillations are in reasonable agreement, and the small difference between them was explained by a magnetic-field-dependent effective g factor. The zero-field spin splitting shows nonmonotonic behavior with a maximum as the electron density is varied with the applied gate voltage. This is related to strong Rashba SO coupling in our sample.