Direct determination of mode-projected electron-phonon coupling in the time domain

M X Na; A K Mills; F Boschini; M Michiardi; B Nosarzewski; R P Day; E Razzoli; A Sheyerman; M Schneider; G Levy; S Zhdanovich; T P Devereaux; A F Kemper; D J Jones; A Damascelli

doi:10.1126/science.aaw1662

Direct determination of mode-projected electron-phonon coupling in the time domain

Science. 2019 Dec 6;366(6470):1231-1236. doi: 10.1126/science.aaw1662.

Authors

M X Na^#^{1

2}, A K Mills^#^{1

2}, F Boschini^{1

2}, M Michiardi^{1

2

3}, B Nosarzewski⁴, R P Day^{1

2}, E Razzoli^{1

2}, A Sheyerman^{1

2}, M Schneider^{1

2}, G Levy^{1

2}, S Zhdanovich^{1

2}, T P Devereaux⁴, A F Kemper⁵, D J Jones^{6

2}, A Damascelli^{6

2}

Affiliations

¹ Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1, Canada.
² Quantum Matter Institute, Vancouver, BC V6T 1Z4, Canada.
³ Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany.
⁴ Department of Materials Science and Engineering, Stanford Institute for Materials and Energy Sciences, Stanford, CA 94305, USA.
⁵ Department of Physics, North Carolina State University, Raleigh, NC 27695, USA.
⁶ Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1, Canada. djjones@physics.ubc.ca damascelli@physics.ubc.ca.

^# Contributed equally.

PMID: 31806810
DOI: 10.1126/science.aaw1662

Abstract

Ultrafast spectroscopies have become an important tool for elucidating the microscopic description and dynamical properties of quantum materials. In particular, by tracking the dynamics of nonthermal electrons, a material's dominant scattering processes can be revealed. Here, we present a method for extracting the electron-phonon coupling strength in the time domain, using time- and angle-resolved photoemission spectroscopy (TR-ARPES). This method is demonstrated in graphite, where we investigate the dynamics of photoinjected electrons at the [Formula: see text] point, detecting quantized energy-loss processes that correspond to the emission of strongly coupled optical phonons. We show that the observed characteristic time scale for spectral weight transfer mediated by phonon-scattering processes allows for the direct quantitative extraction of electron-phonon matrix elements for specific modes.

Publication types

Research Support, Non-U.S. Gov't