Effective doublon and hole temperatures in the photo-doped dynamic Hubbard model

TL;DR

This paper investigates how photo-doping affects doublon and hole populations in the dynamic Hubbard model, revealing different effective temperatures and complex relaxation behaviors influenced by boson coupling.

Contribution

It applies nonequilibrium dynamical mean field theory to analyze temperature dynamics of carriers in the dynamic Hubbard model, highlighting novel energy exchange phenomena.

Findings

Doublon and hole populations attain different effective temperatures after photodoping.

In the polaronic regime, holes can exhibit negative temperature distributions.

Relaxation dynamics depend on boson coupling strength and energy.

Abstract

Hirsch's dynamic Hubbard model describes the effect of orbital expansion with occupancy by coupling the doublon operator to an auxiliary boson. We use the nonequilibrium dynamical mean field method to study the properties of doublon and hole carriers in this model in the strongly correlated regime. In particular, we discuss how photodoping leads to doublon and hole populations with different effective temperatures, and we analyze the relaxation behavior as a function of the boson coupling and boson energy. In the polaronic regime, the nontrivial energy exchange between doublons, holes and bosons can result in a negative temperature distribution for the holes.