Four-Dimensional Imaging of Lattice Dynamics using Inelastic Scattering

TL;DR

This paper demonstrates that inelastic scattering combined with theoretical simulations can effectively image lattice dynamics in real and momentum space, offering an alternative to traditional time-resolved diffraction methods, especially in challenging environments.

Contribution

The work introduces a novel approach using inelastic scattering and simulations to map lattice dynamics, extending capabilities beyond conventional diffraction techniques.

Findings

Simulated lattice dynamics in germanium match experimental x-ray diffuse scattering results.

The method enables in-situ imaging under various environmental conditions.

Applicable to inelastic neutron scattering where diffraction methods are limited.

Abstract

Time-resolved mapping of lattice dynamics in real- and momentum-space is essential to understand better several ubiquitous phenomena such as heat transport, displacive phase transition, thermal conductivity, and many more. In this regard, time-resolved diffraction and microscopy methods are employed to image the induced lattice dynamics within a pump-probe configuration. In this work, we demonstrate that inelastic scattering methods, with the aid of theoretical simulation, are competent to provide similar information as one could obtain from the time-resolved diffraction and imaging measurements. To illustrate the robustness of the proposed method, our simulated result of lattice dynamics in germanium is in excellent agreement with the time-resolved x-ray diffuse scattering measurement performed using x-ray free-electron laser. For a given inelastic scattering data in energy and momentum space, the proposed method is useful to image in-situ lattice dynamics under different environmental conditions of temperature, pressure, and magnetic field. Moreover, the technique will profoundly impact where time-resolved diffraction within the pump-probe setup is not feasible, for instance, in inelastic neutron scattering.