Dephasing Time of Two-Dimensional Holes in GaAs Open Quantum Dots

TL;DR

This study measures the dephasing time of two-dimensional holes in GaAs quantum dots, revealing temperature-dependent coherence effects and differences from electron behavior, advancing understanding of hole-based quantum transport.

Contribution

First measurement of hole dephasing times in GaAs quantum dots using magnetotransport and random matrix theory analysis.

Findings

Dephasing time $ au_$ shows a $T$-dependence between $T^{-1}$ and $T^{-2}$.

Hole dephasing times are about ten times shorter than those of electrons.

Signatures of coherent transport include conductance fluctuations and weak antilocalization.

Abstract

We report magnetotransport measurements of two-dimensional holes in open quantum dots, patterned either as a single-dot or an array of dots, on a GaAs quantum well. For temperatures $T$ below 500 mK, we observe signatures of coherent transport, namely, conductance fluctuations and weak antilocalization. From these effects, the hole dephasing time $\tau_\phi$ is extracted using the random matrix theory. While $\tau_\phi$ shows a $T$-dependence that lies between $T^{-1}$ and $T^{-2}$, similar to that reported for electrons, its value is found to be approximately one order of magnitude smaller.