Signatures of Rashba and Rashba-Edelstein effect in charge and spin transport properties of elemental Bismuth thin films
ORAL
Abstract
The (111) surface of elemental bismuth has been associated with a large Rashba spin-orbit coupling that can lead to significant spin polarization of carriers, and also conversion of charge currents to spin-accumulation via the Rashba-Edelstein (RE) effect. However, direct evidence for the RE effect in transport properties has been lacking. Using magnetotransport measurements, we present evidence for high-mobility, two-dimensional surface states in epitaxially grown Bi (111) thin films, that begin to dominate charge transport below a characteristic temperature Ts ~ 100 K. We also conduct spin-torque ferromagnetic resonance (ST-FMR) measurements on Bi (111)/Permalloy bilayers. We observe a significant increase in the damping like torque below Ts, consistent with enhanced spin transport across the Bi/Permalloy interface. We relate our observations to the spin-momentum locking at Bi (111) surfaces.
*All work at Argonne was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. The use of facilities at the Center for Nanoscale Materials, an Office of Science user facility, was supported by the U.S. Department of Energy, Basic Energy Sciences under contract No. DEAC02-06CH11357.
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Presenters
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Eugene D Ark
- Argonne National Laboratory