Nanoscale Structural Dynamics Probed by Coherent Ultrafast TEM

Abstract

Electron microscopy is tremendously successful in unravelling material structures and compositions on the atomic scale, with a temporal resolution governed by detector response times. Utilizing a stroboscopic approach, ultrafast electron diffraction [1] and microscopy [2] techniques provide for a unique access to processes on ultrashort time scales. In ultrafast transmission electron microscopy (UTEM), combining nanoscale spatial resolution of electron microscopy with femtosecond temporal resolution of optical spectroscopy, a pulsed electron beam of sub-picosecond duration is able to probe rapid processes. Drastically enhancing the achievable beam brightness in UTEM, the recent implementation of laser-triggered field emitters enables an advancement of the UTEM methodology towards coherent electron beam techniques [3].