Photo-induced states in a Mott insulator

TL;DR

This paper explores the properties of photo-doped Mott insulators, revealing that they behave as bad metals with high scattering rates and broad spectral features, differing from chemically doped systems.

Contribution

It provides a detailed analysis of the non-equilibrium states in photo-doped Mott insulators, highlighting their bad metal behavior and contrasting spectral properties.

Findings

Photo-doped Mott insulators exhibit a non-zero, temperature-independent scattering rate.

Spectral functions show broad bands unlike well-defined quasiparticles.

Strong doublon-hole interactions inhibit Fermi-liquid behavior.

Abstract

We investigate the properties of the metallic state obtained by photo-doping carriers into a Mott insulator. In a strongly interacting system, these carriers have a long life-time, so that they can dissipate their kinetic energy to a phonon bath. In the relaxed state, the scattering rate saturates at a non-zero temperature-independent value, and the momentum-resolved spectral function features broad bands which differ from the well-defined quasi-particle bands of a chemically doped system. Our results indicate that a photo-doped Mott insulator behaves as a bad metal, in which strong scattering between doublons and holes inhibits Fermi-liquid behavior down to low temperature.