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