Shubnikov-de Haas oscillations of high mobility holes in monolayer and bilayer WSe₂: Landau level degeneracy, effective mass, and negative compressibility

2016/02/02 by Babak Fallahazad, Hema C. P. Movva, Kyounghwan Kim +5 · 1 citation
Physics and Astronomy · #cond-mat.mes-hall #cond-mat.str-el

paper · pdf · doi:10.1103/physrevlett.116.086601

published as Phys. Rev. Lett. 116, 086601 (2016) · 5 pages, 4 figures

arxiv created 2016/02/02 · arxiv updated 2016/02/25

Abstract

We study the magnetotransport properties of high mobility holes in monolayer and bilayer WSe₂, which display well defined Shubnikov-de Haas (SdH) oscillations, and quantum Hall states (QHSs) in high magnetic fields. In both mono and bilayer WSe₂, the SdH oscillations and the QHSs occur predominantly at even filling factors, evincing a two-fold Landau level degeneracy. The Fourier transform analysis of the SdH oscillations in bilayer WSe₂ reveal the presence of two subbands localized in the top or the bottom layer, as well as negative compressibility. From the temperature dependence of the SdH oscillations we determine a hole effective mass of 0.45m₀ for both mono and bilayer WSe₂.

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