APS Logo

Interplay of hot electron and phonon dynamics in 1<i>T</i>-VSe<sub>2</sub> probed by time- and angle-resolved photoemission spectroscopy

ORAL

Abstract

The charge density wave (CDW) phase of bulk 1T-VSe2 gives rise to only subtle spectroscopic signatures [1-2], leaving unresolved the debate about dominant interactions driving the transition [3]. Here, we optically excite this material with an intense infrared femtosecond pulse, taking it out of its equilibrium CDW state, and probe the evolution of the transient quasiparticle dispersion with time- and angle-resolved photoemission spectroscopy. By monitoring the relaxation of light-induced hot electrons, we extract the time-dependent hot carrier temperature and find that the excited electrons reach a metastable thermal equilibrium with a strongly-coupled optical phonon mode on the timescale of 200 fs. The increase in hot phonon population available to scatter with photoholes leads to an increased linewidth of quasiparticle bands across the entire valence spectrum. We elucidate the role of electron-phonon interactions on the dynamics in this system and discuss the implications of our observations for the response to strong optical excitation in related CDW systems.

[1] Jolie, et al., Phys. Rev. B 99, 115417 (2019).
[2] Strocov, et al., Phys. Rev. Lett. 109, 086401 (2012).
[3] Henke, arXiv: 1911.11112v2 (2019).

–

Presenters

  • Paulina Majchrzak

    Department of Physics and Astronomy, Aarhus University

Authors

  • Paulina Majchrzak

    Department of Physics and Astronomy, Aarhus University

  • Sahar Pakdel

    Department of Physics and Astronomy, Aarhus University, Aarhus University

  • Deepnarayan Biswas

    Department of Physics and Astronomy, Aarhus University

  • Alfred Jones

    Department of Physics and Astronomy, Aarhus University

  • Klara Volckaert

    Department of Physics and Astronomy, Aarhus University

  • Igor Markovic

    School of Physics and Astronomy, University of St Andrews

  • Federico Andreatta

    Department of Physics and Astronomy, Aarhus University

  • Raman Sankar

    National Taiwan University, Insitute of Physics, Academia Sinica

  • Chris Jozwiak

    Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, USA, Lawrence Berkeley National Laboratory, Advanced Light Source, Lawrence Berkeley National Laboratory, Advanced Light Source, Advanced Light Source, Lawrence Berkeley National Lab

  • Eli Rotenberg

    Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, USA, Lawrence Berkeley National Laboratory, Lawrence Berkeley National Lab, Advanced Light Source, Advanced Light Source, Lawrence Berkeley National Laboratory, Advanced Light Source, Advanced Light Source, Lawrence Berkeley National Lab, LBNL

  • Aaron Bostwick

    Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, USA, Advanced Light Source, Lawrence Berkeley National Laboratory, Advanced Light Source, Advanced Light Source, Lawrence Berkeley National Lab

  • Charlotte Sanders

    Artemis Program, UK Central Laser Facility, Central Laser Facility, Rutherford Appleton Laboratory

  • Yu Zhang

    Artemis Program, UK Central Laser Facility, Central Laser Facility, Rutherford Appleton Laboratory

  • Gabriel Karras

    Central Laser Facility, Rutherford Appleton Laboratory

  • Richard T. Chapman

    Central Laser Facility, Rutherford Appleton Laboratory

  • Adam Wyatt

    Central Laser Facility, Rutherford Appleton Laboratory

  • Emma Springate

    Central Laser Facility, Rutherford Appleton Laboratory

  • Jill A. Miwa

    Department of Physics and Astronomy, Aarhus University

  • Philip Hofmann

    Department of Physics and Astronomy, Aarhus University

  • Philip King

    Univ of St Andrews, School of Physics and Astronomy, University of St Andrews

  • Nicola Lanata

    Department of Physics and Astronomy, Aarhus University, Aarhus University

  • Young Jun Chang

    Department of Physics, University of Seoul

  • Søren Ulstrup

    Department of Physics and Astronomy, Aarhus University