# Revealing Hund's multiplets in Mott insulators under strong electric fields

## TL;DR

This paper explores the dynamics of Mott insulators under strong electric fields, revealing how field-induced localization linked to Hund's coupling can be observed and measured in correlated materials.

## Contribution

It predicts the emergence of atomic-like local spin multiplets due to field-induced localization, providing a novel method to measure Hund's coupling in correlated materials.

## Key findings

- Dielectric breakdown occurs via many-body Landau-Zener tunnelling.
- Field-induced localization allows measurement of Hund's coupling J.
- Observable effects in transition metal oxides using time-resolved spectroscopy.

## Abstract

We investigate the strong-field dynamics of a paramagnetic two-band Mott insulator using real-time dynamical mean-field theory. A dielectric breakdown occurs due to many-body Landau-Zener tunnelling, with a threshold field determined by the gap. For a large range of fields, however, we predict that the tunnelling currents are small enough to allow the observation of field-induced localization of electrons, which becomes most strikingly evident in atomic-like local spin multiplets determined by the Hund's coupling $J$. This field-induced localization might provide a way of measuring the value of $J$ in correlated materials. It should be observable in transition metal oxides using time-resolved photo-emission spectroscopy or optical measurements in the presence of strong THz field transients.