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

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 ${\tau }_{\varphi }$ is extracted using the random matrix theory. While ${\tau }_{\varphi }$ 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.

5 pages, 4 figures