Impact of Auger processes on carrier dynamics in graphene

TL;DR

This paper investigates how Auger processes influence carrier dynamics in graphene, revealing efficient impact excitation, carrier multiplication, and Coulomb-induced cooling, with an analytic model predicting conditions for experimental observation.

Contribution

It provides a detailed microscopic analysis of Auger processes in graphene and introduces an analytic expression for carrier multiplication under ideal conditions.

Findings

Efficient impact excitation leads to carrier multiplication.

Coulomb interactions induce significant carrier cooling.

Analytic expression predicts conditions for observing carrier multiplication.

Abstract

The linear, gapless bandstructure of graphene provides ideal conditions for Auger processes. They are of great importance for fundamental research and technological applications, since they qualitatively change the carrier dynamics. Time-, momentum-, and angle-resolved microscopic calculations reveal an efficient impact excitation giving rise to a significant multiplication of optically excited carriers and a remarkable Coulomb- induced carrier cooling effect. We present an analytic expression for the carrier multiplication predicting ideal conditions for its still missing experimental observation.