Coherent control of the orbital occupation driving the insulator-to-metal Mott transition in V$_2$O$_3$

TL;DR

This study demonstrates coherent control of the insulator-to-metal transition in V₂O₃ using phase-locked light pulses to manipulate orbital occupations, revealing an electronic coherence time of about 5 fs and its temperature dependence.

Contribution

It introduces a method for coherent electronic control of phase transitions in quantum materials via selective optical excitation and compares experimental results with theoretical models.

Findings

Electronic coherence time is approximately 5 femtoseconds.

Coherence is enhanced near the transition's critical temperature.

Selective optical excitation can manipulate orbital occupations effectively.

Abstract

Managing light-matter interactions on timescales faster than the loss of electronic coherence is key for achieving full quantum control of the final products in solid-solid transformations. In this work, we demonstrate coherent electronic control of the photoinduced insulator-to-metal transition in the prototypical Mott insulator V$_2$O$_3$. Selective excitation of a specific interband transition with two phase-locked light pulses manipulates the orbital occupation of the correlated bands in a way that depends on the coherent evolution of the photoinduced superposition of states. A comparison between experimental results and numerical solutions of the optical Bloch equations provides an electronic coherence time on the order of 5 fs. Temperature-dependent experiments suggest that the electronic coherence time is enhanced in the vicinity of the insulator-to-metal transition critical temperature, thus highlighting the role of fluctuations in determining the electronic coherence. These results open new routes to selectively switch the functionalities of quantum materials and coherently control solid-solid electronic transformations.