Influence of local symmetry on lattice dynamics of topological surface states

ORAL

Abstract

We investigate coupled electron-lattice dynamics in the topological insulator Bi2Te3 with time- and angle-resolved photoemission spectroscopy (trARPES). It is well established that coherent phonons can be launched by optical excitation, but selection rules typically restrict these modes to specific wavevectors (q~0) and symmetries (Raman-active).  We find that the topological surface state in Bi2Te3 couples to coherent modes that are forbidden in the bulk, including infrared active phonons as well as those with non-zero wavevectors. Our calculations show that these behaviors naturally arise as a consequence of the translational and inversion symmetries broken at the surface. These effects are important to consider when interpreting ultrafast experiments, and may expand the phase space for tailoring material properties on-demand.

*This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division.

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Presenters

  • Jonathan A Sobota

    • Stanford University
    • Geballe Laboratory for Advanced Materials, Stanford University, USA
    • SLAC National Accelerator Lab

Authors

  • Jonathan A Sobota

    • Stanford University
    • Geballe Laboratory for Advanced Materials, Stanford University, USA
    • SLAC National Accelerator Lab

  • Samuel W Teitelbaum

    • Arizona State University

  • Yijing Huang

    • Stanford Univ

  • Jose D Querales-Flores

    • Univ Coll Cork

  • Robert Power

    • University College Cork

  • Meabh Allen

    • University College Cork

  • Costel R Rotundu

    • Stanford University
    • Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, USA
    • SLAC - Natl Accelerator Lab
    • SLAC National Accelerator Lab
    • Stanford

  • Trevor P Bailey

    • University of Michigan

  • Mason Jiang

    • Stanford University

  • Diling Zhu

    • SLAC - Natl Accelerator Lab

  • Matthieu Chollet

    • SLAC - Natl Accelerator Lab
    • SLAC National Accelerator Lab

  • Ctirad Uher

    • University of Michigan

  • Tom Henighan

    • Stanford University

  • Takahiro Sato

    • SLAC National Accelerator Lab

  • Mariano Trigo

    • SLAC - Natl Accelerator Lab

  • Éamonn Murray

    • Tyndall National Institute

  • Ivana Savic

    • Univ Coll Cork

  • Patrick S Kirchmann

    • Geballe Laboratory for Advanced Materials, Stanford University, USA
    • SLAC - Natl Accelerator Lab

  • Stephen Fahy

    • University College Cork

  • David A Reis

    • Stanford Univ

  • Zhixun Shen

    • Stanford University
    • Geballe Laboratory for Advanced Materials, Stanford University, USA
    • Stanford Univ