Photoinduced excitonic magnetism in a multiorbital Hubbard system

TL;DR

This paper explores how photo-doping in multiorbital Hubbard systems can induce and control excitonic magnetism and ferromagnetic phases out of equilibrium, revealing complex phase behavior.

Contribution

It demonstrates the emergence of nonthermal excitonic magnetic phases in photo-doped systems using nonequilibrium dynamical mean-field theory.

Findings

Photo-doping can induce nonthermal excitonic phases.

Rich phase diagram in photo-doping and crystal field parameters.

Potential for controlling magnetic order via light.

Abstract

Multiorbital Hubbard models with Hund coupling and crystal-field splitting exhibit an instability toward spin-triplet excitonic order in the parameter regime characterized by strong local spin fluctuations. Upon chemical doping, two distinct types of excitonic ferromagnetism have been reported. Using steady-state nonequilibrium dynamical mean-field theory, we demonstrate that photo-doped half-filled systems can host nonthermal counterparts of these excitonic phases and exhibit a rich phase diagram in the space of photo-doping and crystal field splitting. Photo-doping a spin-triplet excitonic insulator provides a route towards nonequilibrium control of magnetic order.