Transport properties of a 1000-nm HgTe film: the interplay of surface and bulk carriers

Abstract

We report on systematic study of transport properties of a 1000-nm HgTe film. Unlike to thinner and strained HgTe films, which are known as high-quality three-dimensional (3D) topological insulators, the film under study is much thicker than the limit of pseudomorphic growth of HgTe on a CdTe substrate. Therefore, it is expected to be fully relaxed and has the band structure of bulk HgTe, i.e., a zero gap semiconductor. Nevertheless, since the bands inversion the two-dimensional (2D) topological surface states are still expected to exist. To check this claim we studied classical and quantum transport response of the system. We demonstrate that by tuning the top-gate voltage one can change the electron-dominating transport to the hole one. The highest electron mobility is found to be more than $300\times 10^3$ cm${}^2$/Vs. The system exhibits Shubnikov-de Haas (SdH) oscillations with a complicated pattern and shows up to 5 independent frequencies in corresponding Fourier spectra. They are attributed to the topological surface states, Volkov-Pankratov states and spin-degenerate bulk states in the accumulation layer near the gate. The observed peculiarities of the quantum transport are the strong SdH oscillations of the Hall resistance, and the suppressed oscillatory response of the topological surface states.

References in corpus (8)

• Terahertz Quantum Hall Effect in a Topological Insulator
• Coexistence of bulk and surface states probed by Shubnikov-de Haas oscillations in Bi${}_2$Se${}_3$ with high charge-carrier density
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• Terahertz Magnetospectroscopy of Cyclotron Resonances from Topological Surface States in Thick Films of Cd${}_x$Hg${}_{1-x}$Te
• Scattering anisotropy in HgTe (013) quantum well
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Cited by in corpus (2)

• Magnetophotogalvanic Effects Driven by Terahertz Radiation in CdHgTe Crystals with Kane Fermions
• Positive Terahertz Photoconductivity in CdHgTe Under Hydrostatic Pressure