Long-Lived Quantum Well State Excitation and Surface Photovoltage Interplay in Topological Insulator

POSTER

Abstract

Topological insulators with Fermi levels doped into the bulk-gap exhibit strong surface band-bending and long-lived surface photovoltage (SPV) effects. Furthermore, in-situ surface doping of the topological insulators Bi2Se3 and Bi2Te3 can lead to strong Rashba-split quantum well states. In this study, we have combined bulk-doping and surface-doping to obtain both a strong surface photovoltage and spin-momentum locked quantum well states. Remarkably, Time- and angle-resolved photoemission spectroscopy reveals an additional pump-induced quantum well state that persists for 100s of picoseconds and coincides with the surface photovoltage, as well as time-dependent modifications to the quantum well states. Our work demonstrates that topological insulators are an exemplary foundation for tunable spin-textures with complex dynamics.

*

Director, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division, of the U.S. Department of Energy, under Contract No. DE-AC02-05CH11231, as part of the Ultrafast Materials Science Program (KC2203)

Gordon and Betty Moore Foundation's EPiQS grant GBMF4838

S.C. was supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE1852814 and DGE1106400

Presenters

  • Samuel Ciocys

    • University of California, Berkeley

Authors

  • Samuel Ciocys

    • University of California, Berkeley

  • Alessandra Lanzara

    • University of California, Berkeley
    • Physics, University of California, Berkeley

  • Ryo Mori

    • University of California, Berkeley