Exploring nonequilibrium phases of photo-doped Mott insulators with Generalized Gibbs ensembles

TL;DR

This paper introduces a generalized Gibbs ensemble framework to study long-lived photo-doped states in Mott insulators, revealing novel non-thermal phases and their properties through systematic equilibrium-based methods.

Contribution

The work develops a new theoretical approach using generalized Gibbs ensembles to analyze non-thermal phases in photo-doped Mott insulators, enabling systematic exploration of their phase diagram.

Findings

Identification of $ta$-pairing and charge density wave phases in the phase diagram.

Physical characterization of the non-thermal phases and their dependence on doping.

Clarification of differences between photo-doped Mott insulators, chemically-doped Mott insulators, and photo-doped semiconductors.

Abstract

Photo-excited strongly correlated systems can exhibit intriguing non-thermal phases, but the theoretical investigation of them poses significant challenges. In this work, we introduce a generalized Gibbs ensemble type description for long-lived photo-doped states in Mott insulators. This framework enables systematic studies of photo-induced phases based on equilibrium methods, as demonstrated here for the one-dimensional extended Hubbard model. We determine the nonequilibrium phase diagram, which features $\eta$-pairing and charge density wave phases in a wide doping range, and reveal physical properties of these phases. We show that the peculiar kinematics of photo-doped carriers, and the interaction between them, play an essential role in the formation of the non-thermal phases, and we clarify the differences between photo-doped Mott insulators, chemically-doped Mott insulators and photo-doped semiconductors. Our results demonstrate a new path for the systematic exploration of nonequilibrium strongly correlated systems and show that photo-doped Mott insulators host different phases than conventional semiconductors.