Probing dynamics in quantum materials with femtosecond x-rays

TL;DR

This paper reviews how femtosecond x-ray techniques, especially from free electron lasers, enable detailed ultrafast studies of structural, electronic, and magnetic dynamics in quantum materials, revealing new nonequilibrium phenomena.

Contribution

It highlights recent experimental advances using femtosecond x-ray pulses to probe ultrafast dynamics in quantum materials, expanding understanding of nonequilibrium states.

Findings

Ultrafast x-ray techniques reveal real-time structural changes.

Femtosecond x-ray studies uncover electronic phase transitions.

Magnetic dynamics are probed with high temporal resolution.

Abstract

Optical pulses are routinely used to drive dynamical changes in the properties of solids. In quantum materials, many new phenomena have been discovered, including ultrafast transitions between electronic phases, switching of ferroic orders and nonequilibrium emergent behaviors such as photo-induced superconductivity. Understanding the underlying non-equilibrium physics requires detailed measurements of multiple microscopic degrees of freedom at ultrafast time resolution. Femtosecond x-rays are key to this endeavor, as they can access the dynamics of structural, electronic and magnetic degrees of freedom. Here, we cover a series of representative experimental studies in which ultrashort x-ray pulses from free electron lasers have been used, opening up new horizons for materials research.