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Quantized surface transport in topological Dirac semimetal films
Shinichi Nishihaya1, Masaki Uchida2,3, Yusuke Nakazawa1
1Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), University of Tokyo, Tokyo, 113-8656, Japan.
Nature Communications
|June 14, 2019
Summary
We observed quantum Hall states in Cd3As2 thin films, revealing bulk state involvement in quantized surface transport. This work enables engineering of Fermi-arc transport in topological semimetals.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Transport
Background:
- Topological materials host unconventional surface states protected by bulk topology.
- Weyl orbits in topological semimetals connect spatially separated Fermi arcs.
- Quantum Hall states in Dirac semimetal Cd3As2 bulk suggest novel quantization phenomena.
Purpose of the Study:
- Investigate surface quantum oscillations and their evolution into quantum Hall states in Cd3As2 thin films.
- Systematically control bulk dimensionality, Fermi energy, and band topology.
- Reveal the role of bulk states in quantized surface transport and quantum Hall degeneracy.
Main Methods:
- Fabrication of Cd3As2 thin film samples.
- Systematic control of sample properties (dimensionality, Fermi energy, band topology).
- Measurement of surface quantum oscillations and quantum Hall effect.
Main Results:
- Observed surface quantum oscillations and their evolution into quantum Hall states.
- Demonstrated essential involvement of bulk states in quantized surface transport.
- Showed quantum Hall degeneracy depends on bulk occupation.
Conclusions:
- Quantized surface transport in Cd3As2 thin films is influenced by bulk states.
- Quantum Hall degeneracy is tunable via bulk occupation.
- Cd3As2 thin films offer a platform for engineering Fermi-arc-mediated transport.
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