Dependence of spin dynamics on in-plane magnetic field in AlGaN/GaN quantum wells

We systematically investigate the weak antilocalization effect and the dependence of spin dynamics on the in-plane magnetic field for two Al_xGa_1-xN/GaN quantum wells, in which these effects are dominated by the spin-orbit interaction originating from the structural inversion asymmetry and the bulk inversion asymmetry, respectively. By fitting the weak antilocalization magnetoconductance, the phase coherence time and spin-orbit scattering time are obtained. With the increase of in-plane magnetic fields, the phase coherence time decreases quadratically while the spin-orbit scattering time increases quadratically. We attribute these variations to the competition between the Zeeman splitting and the spin-orbit interaction. The comparison between systems dominated by structural inversion asymmetry and bulk inversion asymmetry in the in-plane magnetic field is also made. Our findings may provide clues to control the weak antilocalization effect and spin-orbit interaction via the in-plane field.