Optical probing of correlation driven liquid-to-insulator transition in 2D electron gas

TL;DR

This study uses optical and transport techniques to investigate the correlation-driven liquid-to-insulator transition in a high mobility 2D electron gas, revealing changes in screening, symmetry, and effective mass.

Contribution

It provides new insights into the quantum Hall liquid and metal-insulator transition through optical probing of dispersion and screening effects.

Findings

Detection of magneto-Coulomb screening effects.

Observation of linear dispersion in the insulating phase.

Evidence of increased renormalized mass in the insulator.

Abstract

We study the quantum Hall liquid and the metal-insulator transition in a high mobility two dimensional electron gas, by means of photoluminescence and magneto-transport. In the integer and fractional regime at nu > 1/3, analyzing the emission energy dispersion we probe the magneto-Coulomb screening and the hidden symmetry of the electron liquid. In the fractional regime above above nu =1/3 the system undergoes the metal-to-insulator transition, and in the insulating phase the dispersion becomes linear with evidence of an increased renormalized mass.