Temperature dependent effective mass renormalization in 2D electron systems

TL;DR

This paper investigates how the effective mass of electrons in 2D systems varies with temperature and density, revealing unexpected nonanalytic and nonmonotonic behavior due to electron-electron interactions.

Contribution

It introduces a calculation of temperature-dependent effective mass renormalization in 2D electron systems using leading-order dynamically screened Coulomb interactions, highlighting novel nonanalytic effects.

Findings

Effective mass increases linearly with temperature at low temperatures.

Discovery of nonanalytic and nonmonotonic temperature dependence.

Results applicable across various electron densities.

Abstract

We calculate, as a function of temperature and density, the electron-electron interaction induced quasiparticle effective mass renormalization in 2D electron systems within the leading-order dynamically screened Coulomb interaction expansion. We find an unexpected nonanalyticity and nonmonotonicity in the temperature dependent effective mass with the renormalized mass linearly increasing with temperature at low temperatures for all densities.