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Optical manipulation of Rashba-split 2-dimensional electron gas

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  • M. Michiardi, University of British Columbia, Max Planck Institute for Chemical Physics of Solids
  • ,
  • F. Boschini, University of British Columbia, Institut National de la Recherche Scientifique
  • ,
  • H-H Kung, University of British Columbia
  • ,
  • M. X. Na, University of British Columbia
  • ,
  • S. K. Y. Dufresne, University of British Columbia
  • ,
  • A. Currie, University of British Columbia
  • ,
  • G. Levy, University of British Columbia
  • ,
  • S. Zhdanovich, University of British Columbia
  • ,
  • A. K. Mills, University of British Columbia
  • ,
  • D. J. Jones, University of British Columbia
  • ,
  • J. L. Mi
  • ,
  • B. B. Iversen
  • Ph Hofmann
  • A. Damascelli, University of British Columbia

The major challenge for the development of spin based information processing is to obtain efficient ways of controlling spin. Here, Michiardi et al show that the Rashba spin-splitting at the surface of Bi2Se3 topological insulator can be controlled via optical pulses on picosecond timescales.

In spintronics, the two main approaches to actively control the electrons' spin involve static magnetic or electric fields. An alternative avenue relies on the use of optical fields to generate spin currents, which can bolster spin-device performance, allowing for faster and more efficient logic. To date, research has mainly focused on the optical injection of spin currents through the photogalvanic effect, and little is known about the direct optical control of the intrinsic spin-splitting. To explore the optical manipulation of a material's spin properties, we consider the Rashba effect. Using time- and angle-resolved photoemission spectroscopy (TR-ARPES), we demonstrate that an optical excitation can tune the Rashba-induced spin splitting of a two-dimensional electron gas at the surface of Bi2Se3. We establish that light-induced photovoltage and charge carrier redistribution - which in concert modulate the Rashba spin-orbit coupling strength on a sub-picosecond timescale - can offer an unprecedented platform for achieving optically-driven spin logic devices.

Original languageEnglish
Article number3096
JournalNature Communications
Volume13
Issue1
Number of pages7
ISSN2041-1723
DOIs
Publication statusPublished - 2 Jun 2022

    Research areas

  • SURFACE PHOTOVOLTAGE, SPIN, APPROXIMATION

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