Orbital dynamics during an ultrafast insulator to metal transition

TL;DR

This study uses femtosecond time-resolved RIXS to investigate the orbital dynamics of V2O3 during an ultrafast insulator-to-metal transition, revealing rapid electronic changes and the potential of RIXS for probing strongly correlated materials.

Contribution

It demonstrates the application of fs-time-resolved RIXS to observe orbital excitations during ultrafast phase transitions in a Mott insulator.

Findings

Orbital excitations respond within sub-ps timescale after laser excitation.

The electronic state evolves to resemble the high-temperature metallic phase.

RIXS spectroscopy can effectively probe ultrafast orbital dynamics.

Abstract

Phase transitions driven by ultrashort laser pulses have attracted interest both for understanding the fundamental physics of phase transitions and for potential new data storage or device applications. In many cases these transitions involve transient states that are different from those seen in equilibrium. To understand the microscopic properties of these states, it is useful to develop elementally selective probing techniques that operate in the time domain. Here we show fs-time-resolved measurements of V Ledge Resonant Inelastic X-Ray Scattering (RIXS) from the insulating phase of the Mott- Hubbard material V2O3 after ultrafast laser excitation. The probed orbital excitations within the d-shell of the V ion show a sub-ps time response, which evolve at later times to a state that appears electronically indistinguishable from the high-temperature metallic state. Our results demonstrate the potential for RIXS spectroscopy to study the ultrafast orbital dynamics in strongly correlated materials.