New Advances in Stimulated Electron Energy Gain and Loss Spectroscopy

Abstract

This is an Accepted Manuscript for the Microscopy and Microanalysis 2020 Proceedings. This version may be subject to change during the production process.

Accelerating Quantum Materials Development with Advances in Transmission Electron Microscopy

“…EEGS can be combined with energy filtered TEM (EFTEM) imaging offering direct and background free imaging of the evanescent electromagnetic fields such as near-field distribution of surface plasmon resonances (SPRs). , Furthermore, combining stimulated EELS and EEGS, one can precisely measure the local temperature in the illuminated region based on the ratio of electron energy loss and gain (emission and absorption). Examples of studies that have been done leveraging EEGS capabilities in quantum materials include understanding the retardation effect in MgO nanocubes, phonon–electron coupling dynamics in MgO, direct measurement of temperature dependent heat dissipation in hBN, loss and gain of the optical-phonon modes in hBN flakes, and plasmon-electron coupling in plasmonic nanostructures including Ag nanorods and Ag nanoshells. ,,− Care should be taken when considering the local temperature in interpreting such out of equilibrium quantum systems, particularly when considering the effect of local confinement, heterogeneity and coupling of the nonequilibrium states. − Time-resolved capabilities will further extend the ability to disentangle temperature effects when studying excitations and nonequilibrium states in quantum materials. Ultrafast-EELS and ultrafast-EEGS will potentially allow researchers to probe the local temperature at quasi-equilibrium states in strongly correlated systems.…”