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

Abstract

We systematically investigate the weak antilocalization effect and the dependence of spin dynamics on the in-plane magnetic field for two AlxGa1−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.

Zeeman splitting and spin-orbit interaction in Hg1−xCdxTe inversion layers

“…Then the WAL effect vanishes, while the weak localization (WL) effect, related to the pure orbital effect, is still preserved until the Zeeman splitting matches the spin-orbit splitting (g * μ B B // /Δ 0 → 1) [26]. If we only take into account the dephasing caused by Zeeman splitting, we can obtain the |m * r g * 0 | by analyzing the change of τ φ (B // ) over the B // as follows [13,15]:…”

“…Hence, in order to experimentally study the spin dynamics of both Zeeman splitting and SOI, a large in-plane magnetic field (B // ) is needed. The suppression of WAL in the InGaAs quantum wells (QWs) [14] and AlGaN QWs [15] has been studied in the in-plane magnetic field (B // ). However, the competition between Zeeman splitting and SOI in the inversion layer of Hg 1−x Cd x Te has rarely been investigated by magnetotransport measurement.…”