Interference induced metallic-like behavior of a two-dimensional hole gas in asymmetric GaAs/In$_{x}$Ga$_{1-x}$As/GaAs quantum well

TL;DR

This study investigates how interference effects, spin relaxation, and phonon scattering influence the metallic-like conductivity behavior of a two-dimensional hole gas in asymmetric GaAs/InGaAs/GaAs quantum wells across a temperature range of 0.4 to 20 K.

Contribution

It provides a comprehensive explanation of the temperature-dependent conductivity behavior in asymmetric quantum wells, highlighting the roles of interference, interaction, and phonon scattering effects.

Findings

Interference quantum correction dominates at 0.4-1.5 K.

Interaction quantum correction is significant at 1.5-4 K.

Phonon scattering explains metallic-like behavior above 4-6 K.

Abstract

The temperature and magnetic field dependences of the conductivity of the heterostructures with asymmetric In$_x$Ga$_{1-x}$As quantum well are studied. It is shown that the metallic-like temperature dependence of the conductivity observed in the structures investigated is quantitatively understandable within the whole temperature range, $T=0.4-20$ K. It is caused by the interference quantum correction at fast spin relaxation for 0.4 K$ < T < 1.5$ K. At higher temperatures, 1.5 K$<T<4$ K, it is due to the interaction quantum correction. Finally, at $T>4-6$ K, the metallic-like behavior is determined by the phonon scattering.