Mechanisms of electron-phonon coupling unraveled in momentum and time: The case of soft phonons in TiSe 2

The complex coupling between charge carriers and phonons is responsible for diverse phenomena in condensed matter. We apply ultrafast electron diffuse scattering to unravel electron-phonon coupling phenomena in 1T-TiSe in both momentum and time. We are able to distinguish effects due to the real par...

Full description

Saved in:
Bibliographic Details
Published in:Science advances 2021-05, Vol.7 (20)
Main Authors: Otto, Martin R, Pöhls, Jan-Hendrik, René de Cotret, Laurent P, Stern, Mark J, Sutton, Mark, Siwick, Bradley J
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The complex coupling between charge carriers and phonons is responsible for diverse phenomena in condensed matter. We apply ultrafast electron diffuse scattering to unravel electron-phonon coupling phenomena in 1T-TiSe in both momentum and time. We are able to distinguish effects due to the real part of the many-body bare electronic susceptibility, [Formula: see text], from those due to the electron-phonon coupling vertex, , by following the response of semimetallic (normal-phase) 1T-TiSe to the selective photo-doping of carriers into the electron pocket at the Fermi level. Quasi-impulsive and wave vector-specific renormalization of soft zone-boundary phonon frequencies (stiffening) is observed, followed by wave vector-independent electron-phonon equilibration. These results unravel the underlying mechanisms driving the phonon softening that is associated with the charge density wave transition at lower temperatures.
ISSN:2375-2548
2375-2548
DOI:10.1126/sciadv.abf2810