Controlling Spin-Polarized Currents on the Surface of Topological Insulators

ORAL

Abstract

The appearance of topologically protected spin-momentum locked surface states with forbidden backward scattering on the surface of topological insulators gives rise to robust room temperature spin currents making them ideal candidates for the realization of spintronic devices. So far however, despite a decade of research in this field, very little is known on how to access and manipulate such currents in a manner that is accessible in chip-based devices. Here we reveal a technique to generate long-lived spin-currents of arbitrary geometry with tunable magnitude and duration on the surface of Bi2Se3 topological insulators. Time-resolved angle-resolved photoemission spectroscopy, together with a quantitative model, uncovers a remarkable contrast with respect to doping thanks to the intrinsic correlation between the spin-locked surface state and an insulating bulk. This work demonstrates that localized spin-currents are accessible with long lifetimes, easily tuned in both magnitude and duration, merging photonics and spintronics based devices on the same material.

*Funding for this project was provided by the Department of Energy as a part of the Ultrafast Materials Program, additional student funding provided by the NSF Graduate Research Fellowship Program

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Presenters

  • Samuel Ciocys

    • Physics, University of California, Berkeley

Authors

  • Samuel Ciocys

    • Physics, University of California, Berkeley

  • Takahiro Morimoto

    • Physics, University of California, Berkeley

  • Kenneth Gotlieb

    • Applied Sciences and Technology, University of California, Berkeley
    • University of California, Berkeley

  • Zahid Hussain

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

  • James G. Analytis

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

  • Joel Moore

    • University of California, Berkeley
    • Department of Physics, University of California, Berkeley, California 94720, USA
    • University of California, Berkeley and Lawrence Berkeley National Laboratory
    • Physics, University of California, Berkeley
    • University of California, Berkeley, and Lawrence Berkeley National Laboratory

  • Alessandra Lanzara

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