Hole Fermi Surface in Bi₂Se₃ Probed by Quantum Oscillations
Transport and torque magnetometry measurements are performed at high magnetic fields and low temperatures in a series of p-type (Ca-doped) Bi2Se3 crystals. The angular dependence of the Shubnikov-de Haas and de Haas-van Alphen quantum oscillations enables us to determine the Fermi surface of the bulk valence band states as a function of the carrier density. At low density, the angular dependence exhibits a downturn in the oscillations frequency between 0° and 90°, reflecting a bag-shaped hole Fermi surface. The detection of a single frequency for all tilt angles rules out the existence of a Fermi surface with different extremal cross sections down to 24 meV. There is therefore no signature of a camelback in the valence band of our bulk samples, in accordance with the direct band gap predicted by GW calculations.
B. A. Piot et al., "Hole Fermi Surface in Bi₂Se₃ Probed by Quantum Oscillations," Physical review B: Condensed matter and materials physics, vol. 93, no. 15, American Physical Society, Apr 2016.
The definitive version is available at https://doi.org/10.1103/PhysRevB.93.155206
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01 Apr 2016