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Quantum interference mapping of Rashba-split Bloch states in Bi/Ag(111)
L El-Kareh1, P Sessi, T Bathon
1Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany.
Physical Review Letters
|May 18, 2013
Summary
We investigated the Bi/Ag(111) surface alloy, revealing a giant Rashba-type spin splitting. Backscattering occurs both below and above the Rashba energy, with distinct behaviors in occupied and unoccupied electronic states.
Area of Science:
- Condensed Matter Physics
- Surface Science
- Quantum Mechanics
Background:
- Surface alloys provide platforms for studying exotic electronic phenomena.
- Rashba-type spin splitting is crucial for spintronic applications.
- Understanding electron scattering is key to material properties.
Purpose of the Study:
- Investigate the electronic band structure of the (sqrt[3]×sqrt[3]) Bi/Ag(111)R30° surface alloy.
- Characterize the Rashba-type spin splitting and its energy dependence.
- Analyze electron backscattering mechanisms within the alloy.
Main Methods:
- Low-temperature scanning tunneling spectroscopy (LT-STS).
- Quantum interference mapping.
- Analysis of energy dispersion and scattering channels.
Main Results:
- Observed spectroscopic features attributed to two Rashba-split bands.
- Demonstrated that backscattering is allowed below and above the Rashba energy.
- Identified conventional Rashba splitting in unoccupied bands and hybridization in occupied states.
Conclusions:
- The observed phenomena are consistent with the Bloch picture of electronic states.
- The Bi/Ag(111) surface alloy exhibits unique electronic properties due to giant Rashba spin splitting.
- Distinct scattering behaviors in occupied and unoccupied states offer insights into spin-dependent transport.
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