A photo-induced strange metal with electron and hole quasi-particles

TL;DR

This paper investigates the long-time dynamics of photo-induced strange metallic states in correlated materials, revealing non-Fermi liquid behavior, electron-hole asymmetry, and slow energy relaxation relevant for ultrafast transport phenomena.

Contribution

It introduces a detailed study of the evolution of photo-doped strange metals, highlighting the formation of non-Fermi liquid quasiparticles with separate electron and hole Fermi levels.

Findings

Formation of non-Fermi liquid quasiparticles with separate electron and hole Fermi levels

Persistent non-Fermi liquid behavior on picosecond timescales

Asymmetry and strong correlations between electrons and holes

Abstract

Photo-doping of Mott insulators or correlated metals can create an unusual metallic state which simultaneously hosts hole-like and electron-like particles. We study the dynamics of this state up to long times, as it passes its kinetic energy to the environment. When the system cools down, it crosses over from a bad metal into a resilient quasiparticle regime, in which quasiparticle bands are formed with separate Fermi levels for electrons and holes, but quasiparticles do not yet satisfy the Fermi liquid paradigm. Subsequently, the transfer of energy to the environment slows down significantly, and the system does not reach the Fermi liquid state even on the timescale of picoseconds. The transient photo-doped strange metal exhibits unusual properties of relevance for ultrafast charge and heat transport: In particular, there can be an asymmetry in the properties of electrons and holes, and strong correlations between electrons and holes, as seen in the spectral properties.