Thermodynamic Signature of a Two-Dimensional Metal-Insulator Transition

TL;DR

This study investigates the thermodynamic properties of a two-dimensional hole system undergoing a metal-insulator transition, revealing critical behavior and phase diagram evolution under magnetic fields.

Contribution

It provides the first detailed thermodynamic analysis of the transition, highlighting the compressibility change and phase diagram construction under varying magnetic fields.

Findings

dK/dp changes sign at critical density

Insulating phase is incompressible for all magnetic fields

Phase diagram shows evolution of transition with magnetic field

Abstract

We present a study of the compressibility, K, of a two-dimensional hole system which exhibits a metal-insulator phase transition at zero magnetic field. It has been observed that dK/dp changes sign at the critical density for the metal-insulator transition. Measurements also indicate that the insulating phase is incompressible for all values of B. Finally, we show how the phase transition evolves as the magnetic field is varied and construct a phase diagram in the density-magnetic field plane for this system.