APS Logo

Ultrafast Dynamics in Normal and CDW States of 2H-NbSe<sub>2</sub>

ORAL

Abstract

We have performed femtosecond pump-probe reflectivity study of the carrier and lattice dynamics using near-IR pump and white broadband probe at temperatures below and above the charge density wave transition in single crystal NbSe2. The temperature dependence of the frequency of the coherent damped oscillations show a second order softening when approaching TCDW. This mode can be described as a combination of two acoustic phonons, one of which has Kohn anomaly in a broad range of temperatures. We extracted basic characteristics of the soft mode and its anharmonic decay. Global analysis fits from femtosecond to nanosecond scale were applied to describe the relaxation dynamics from the broadband transient reflectivity data.

–

Presenters

  • Goran Karapetrov

    Physics and Materials Science and Engineering, Drexel University, Department of Physics & Department of Materials Science and Engineering, Drexel University, Physics and Materials Science and Engineering, Drexel Univiversity

Authors

  • Goran Karapetrov

    Physics and Materials Science and Engineering, Drexel University, Department of Physics & Department of Materials Science and Engineering, Drexel University, Physics and Materials Science and Engineering, Drexel Univiversity

  • Anton Anikin

    Physics, Drexel University

  • Richard D Schaller

    Department of Chemistry, Northwestern University, Center for Nanoscale Materials, Argonne National Laboratory, Advanced Photon Source, Argonne National Laboratory

  • Gary P Wiederrecht

    Center for Nanoscale Materials, Argonne National Laboratory