Gate-controlled weak antilocalization effect in inversion layer on p-type HgCdTe

TL;DR

This study reports the observation of weak antilocalization in a two-dimensional electron gas on p-type HgCdTe, analyzing spin-orbit interactions and decoherence mechanisms through gate-controlled experiments.

Contribution

It introduces the first observation of weak antilocalization in the inversion layer on p-type HgCdTe and characterizes the spin-orbit coupling and decoherence mechanisms in this system.

Findings

Weak antilocalization observed in p-type HgCdTe inversion layer

Elliot-Yafet and Nyquist mechanisms dominate spin decoherence and dephasing

Rashba parameter is large with non-monotonic dependence on carrier density

Abstract

We discover weak antilocalization effect of two-dimensional electron gas with one electric subband occupied in the inversion layer on p-type HgCdTe crystal. By fitting the model of Iordanskii, Lyanda-Geller and Pikus to data at varies temperatures and gate voltages, we extract phase coherence and spin-orbit scattering times as functions of temperature and carrier density. We find that Elliot-Yafet mechanism and Nyquist mechanism are the dominating spin decoherence and dephasing mechanisms, respectively. We also find that the Rashba parameter is relatively large and the dependence of Rashba parameter upon carrier density is not monotonic and an optimal carrier density exists for the maximization of spin-orbit coupling.