Coulomb scattering lifetime of a two-dimensional electron gas

TL;DR

This paper calculates the inelastic quasiparticle lifetime in a 2D electron gas due to Coulomb interactions, resolving discrepancies with recent tunneling experiments by correcting previous theoretical errors.

Contribution

It provides a precise theoretical calculation of electron-electron scattering rates in 2D systems using RPA, aligning well with experimental data without adjustable parameters.

Findings

Excellent agreement with experimental scattering rates

Identifies errors in previous theoretical work

Highlights importance of off-shell energy dependence

Abstract

Motivated by a recent tunneling experiment in a double quantum-well system, which reports an anomalously enhanced electronic scattering rate in a clean two-dimensional electron gas, we calculate the inelastic quasiparticle lifetime due to electron-electron interaction in a single loop dynamically screened Coulomb interaction within the random-phase-approximation. We obtain excellent quantitative agreement with the inelastic scattering rates in the tunneling experiment without any adjustable parameter, finding that the reported large ($\geq$ a factor of six) disagreement between theory and experiment arises from quantitative errors in the existing theoretical work and from the off-shell energy dependence of the electron self-energy.