Non-equilibrium dynamics in the antiferromagnetic Hubbard model

TL;DR

This paper studies the out-of-equilibrium behavior of the antiferromagnetic Hubbard model after a sudden change in interaction strength, revealing persistent magnetic order and a dynamical transition between coherent and incoherent magnetic states.

Contribution

It demonstrates the survival of magnetic order beyond thermal expectations and identifies a dynamical transition between different magnetic regimes using the time-dependent Gutzwiller approximation.

Findings

Magnetic order persists longer than thermalization predicts.

Evidence of a dynamical transition at large U values.

Transition from coherent to incoherent antiferromagnetic states.

Abstract

We investigate by means of the time-dependent Gutzwiller approximation the out-of-equilibrium dynamics of an antiferromagnetic state evolved with the Hubbard model Hamiltonian after a sudden change of the repulsion strength $U$. We find that magnetic order survives more than what expected on the basis of thermalization arguments, in agreement with recent DMFT calculations. In addition, we find evidence of a dynamical transition for quenches to large values of $U$ between a coherent antiferromagnet characterized by a finite quasiparticle residue to an incoherent one with vanishing residue, that finally turns into a paramagnet for even larger $U$.