Slow down of the electronic relaxation close to the Mott transition

TL;DR

This paper studies how electronic relaxation slows down near the Mott transition after a quench, revealing a bottleneck timescale that can vastly exceed electronic hopping times, challenging traditional separation of electronic and lattice dynamics.

Contribution

It identifies a purely electronic bottleneck timescale near the Mott transition using nonequilibrium dynamical mean-field theory and slave-rotor methods, highlighting non-linear spectral weight dependence.

Findings

Electronic bottleneck timescale can be orders of magnitude larger than hopping time

Separation of electronic and lattice timescales may break down near the transition

Relaxation dynamics are governed by spectral weight around the Fermi energy

Abstract

We investigate the time-dependent reformation of the quasiparticle peak in a correlated metal near the Mott transition, after the system is quenched into a hot electron state and equilibrates with an environment which is colder than the Fermi-liquid crossover temperature. Close to the transition, we identify a purely electronic bottleneck timescale, which depends on the spectral weight around the Fermi energy in the bad metallic phase in a non-linear way. This timescale can be orders of magnitude larger than the bare electronic hopping time, so that a separation electronic and lattice timescales may break down. The results are obtained using nonequilibrium dynamical mean-field theory and a slave-rotor representation of the Anderson impurity model.