Dephasing time of two-dimensional holes in GaAs open quantum dots: Magnetotransport measurements

We report magnetotransport measurements of two-dimensional holes in open quantum dots, patterned as either 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 τ_ϕ together with an upper limit for the spin-orbit scattering time are extracted using the random matrix theory. The calculated τ_ϕ shows a T dependence close to T⁻², and its absolute value is found to be approximately one order of magnitude smaller than that reported for electrons.