Optical manipulation of Rashba-split 2-dimensional electron gas

M Michiardi; F Boschini; H-H Kung; M X Na; S K Y Dufresne; A Currie; G Levy; S Zhdanovich; A K Mills; D J Jones; J L Mi; B B Iversen; Ph Hofmann; A Damascelli

doi:10.1038/s41467-022-30742-5

Optical manipulation of Rashba-split 2-dimensional electron gas

Nat Commun. 2022 Jun 2;13(1):3096. doi: 10.1038/s41467-022-30742-5.

Authors

M Michiardi^{1

2

3}, F Boschini^{4

5

6}, H-H Kung^{4

5}, M X Na^{4

5}, S K Y Dufresne^{4

5}, A Currie^{4

5}, G Levy^{4

5}, S Zhdanovich^{4

5}, A K Mills^{4

5}, D J Jones^{4

5}, J L Mi⁷, B B Iversen⁷, Ph Hofmann⁸, A Damascelli^{9

10}

Affiliations

¹ Quantum Matter Institute, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada. mmichiardi@phas.ubc.ca.
² Department of Physics & Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada. mmichiardi@phas.ubc.ca.
³ Max Planck Institute for Chemical Physics of Solids, Dresden, Germany. mmichiardi@phas.ubc.ca.
⁴ Quantum Matter Institute, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
⁵ Department of Physics & Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada.
⁶ Centre Énergie Matériaux Télécommunications, Institut National de la Recherche Scientifique, Varennes, QC, J3X 1S2, Canada.
⁷ Department of Chemistry, Aarhus University, 8000, Aarhus C, Denmark.
⁸ Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, 8000, Aarhus C, Denmark.
⁹ Quantum Matter Institute, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada. damascelli@physics.ubc.ca.
¹⁰ Department of Physics & Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada. damascelli@physics.ubc.ca.

Abstract

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.

Abstract

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