QDev Seminar: Fabrizio Nichele

Transport experiment in p-type GaAs

Semiconductor nanostructures implemented in two-dimensional systems with large spin-orbit interaction (SOI) are considered as potential building blocks for the realization of quantum information processing and various spintronic devices. In this framework, p-type GaAs/AlGaAs heterostructures offer the unique opportunity to study SOI induced effects in a material system that can be grown with high control and reliably patterned into nanostructures.

SOI breaks the total angular momentum degeneracy already at zero magnetic field, resulting in a band-warping. Accordingly spin and momentum eigenstates mix, leading to a profound difference between the two SOI-split bands. In my talk I will show how one can separately measure the effective masses of the two SOI-split bands from standard magneto-transport experiments, and discuss the differences with respect to a SOI-free electron system. I will then focus my attention on recent transport experiments performed in p-type GaAs nanostructures, where the strong SOI resulted in peculiar transport phenomena.