Bulk Cyclotron Resonance in the Topological Insulator Bi2Te3

Crystals

HadjM. Benia¹  DmytroL. Kamenskyi²  YuriiG. Selivanov³  VictorP. Martovitskii³  KirillS. Pervakov³  ArtemV. Pronin⁴ 

[1] Centre de Développement des Technologies Avancées (CDTA), Baba Hassen, 16081 Algiers, Algeria;High Field Magnet Laboratory (HFML-EMFL), Radboud University, 6525 ED Nijmegen, The Netherlands;P. N. Lebedev Physical Institute of the RAS, 119991 Moscow, Russia;Physikalisches Institut, Universität Stuttgart, 70569 Stuttgart, Germany;

关键词: topological insulators;    cyclotron resonance;    Dirac materials;   

DOI  :  10.3390/cryst10090722

来源: DOAJ

【 摘 要 】

We investigated magneto-optical response of undoped Bi₂Te₃ films in the terahertz frequency range (0.3–5.1 THz, 10–170 cm⁻¹) in magnetic fields up to 10 T. The optical transmission, measured in the Faraday geometry, is dominated by a broad Lorentzian-shaped mode, whose central frequency linearly increases with applied field. In zero field, the Lorentzian is centered at zero frequency, representing hence the free-carrier Drude response. We interpret the mode as a cyclotron resonance (CR) of free carriers in Bi₂Te₃. Because the mode’s frequency position follows a linear magnetic-field dependence and because undoped Bi₂Te₃ is known to possess appreciable number of bulk carriers, we associate the mode with a bulk CR. In addition, the cyclotron mass obtained from our measurements fits well the literature data on the bulk effective mass in Bi₂Te₃. Interestingly, the width of the CR mode demonstrates a behavior non-monotonous in field. We propose that the CR width is defined by two competing factors: impurity scattering, which rate decreases in increasing field, and electron-phonon scattering, which exhibits the opposite behavior.

【 授权许可】

Unknown