Time-dependent Mott transition in the periodic Anderson model with nonlocal hybridization

TL;DR

This paper investigates the real-time dynamics of a time-dependent Mott transition in a periodic Anderson model with nonlocal hybridization, revealing an orbital-selective transition and its relation to equilibrium behavior.

Contribution

It introduces a nonequilibrium self-energy functional approach to study the dynamical Mott transition with off-site hybridization, highlighting the orbital selectivity and connection to equilibrium transitions.

Findings

The transition is orbital selective, with the Mott gap opening only in localized orbitals.

The critical interaction and effective temperature depend on hybridization strength.

A smooth crossover from quenched to quasi-static processes connects nonequilibrium and equilibrium transitions.

Abstract

The time-dependent Mott transition in a periodic Anderson model with off-site, nearest-neighbor hybridization is studied within the framework of nonequilibrium self-energy functional theory. Using the two-site dynamical-impurity approximation, we compute the real-time dynamics of the optimal variational parameter and of different observables initiated by sudden quenches of the Hubbard-U and identify the critical interaction. The time-dependent transition is orbital selective, i.e., in the final state, reached in the long-time limit after the quench to the critical interaction, the Mott gap opens in the spectral function of the localized orbitals only. We discuss the dependence of the critical interaction and of the final-state effective temperature on the hybridization strength and point out the various similarities between the nonequilibrium and the equilibrium Mott transition. It is shown that these can also be smoothly connected to each other by increasing the duration of a U-ramp from a sudden quench to a quasi-static process. The physics found for the model with off-site hybridization is compared with the dynamical Mott transition in the single-orbital Hubbard model and with the dynamical crossover found for the real-time dynamics of the conventional Anderson lattice with on-site hybridization.