Metal Insulator transition at B=0 in p-SiGe

TL;DR

This paper reports the observation of a metal-insulator transition at zero magnetic field in a high mobility two-dimensional hole gas in strained SiGe quantum wells, showing behaviors similar to those in Si-MOSFETs.

Contribution

It provides experimental evidence of a metal-insulator transition at B=0 in p-SiGe, highlighting similarities with Si-MOSFETs and expanding understanding of 2D electronic phase transitions.

Findings

Resistivity decreases exponentially with temperature in the metallic phase.

Duality between resistivity and conductivity across the transition.

Transition observed at zero magnetic field in high mobility p-SiGe samples.

Abstract

Observations are reported of a metal-insulator transition in a 2D hole gas in asymmetrically doped strained SiGe quantum wells. The metallic phase, which appears at low temperatures in these high mobility samples, is characterised by a resistivity that decreases exponentially with decreasing temperature. This behaviour, and the duality between resistivity and conductivity on the two sides of the transition, are very similar to that recently reported for high mobility Si-MOSFETs.