Landau level spectroscopy of Bi${}_2$Te${}_3$

Abstract

Here we report on Landau level spectroscopy in magnetic fields up to 34 T performed on a thin film of topological insulator Bi${}_2$Te${}_3$ epitaxially grown on a BaF${}_2$ substrate. The observed response is consistent with the picture of a direct-gap semiconductor in which charge carriers closely resemble massive Dirac particles. The fundamental band gap reaches $E_g=(175\pm 5)$~meV at low temperatures and it is not located on the trigonal axis, thus displaying either six or twelvefold valley degeneracy. Notably, our magneto-optical data do not indicate any band inversion. This suggests that the fundamental band gap is relatively distant from the $\Gamma$ point where profound inversion exists andgives rise to relativistic-like surface states of Bi${}_2$Te${}_3$.

12 pages, 11 figures, to be published in Phys. Rev. B

References in corpus (8)

• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Quasi-classical cyclotron resonance of Dirac fermions in highly doped graphene
• Magneto-optics of massive Dirac fermions in bulk Bi2Se3
• Bulk Band Structure of Bi${}_2$Te${}_3$
• Fine structure of "zero-mode" Landau levels in HgTe/HgCdTe quantum wells
• Anisotropic effect of warping on the lifetime broadening of topological surface states in angle-resolved photoemission from Bi${}_2$Te${}_3$
• Infrared electrodynamics and ferromagnetism in the topological semiconductors Bi${}_2$Te${}_3$ and Mn-doped Bi${}_2$Te${}_3$

Cited by in corpus (3)

• Semi-Dirac Fermions in a Topological Metal
• Electronic band structure of Sb2Te3
• Anisotropy in the dielectric function of Bi${}_2$Te${}_3$ from first principles: From the UV-visible to the infrared range