Giant plateau in the THz Faraday angle in gated Bi2Se3

Abstract

We report gated terahertz Faraday angle measurements on epitaxial Bi2Se3 thin films capped with In2Se3. A plateau is observed in the real part of the Faraday angle at an onset gate voltage corresponding to no band bending at the surface which persists into accumulation. The plateau is two orders of magnitude flatter than the step size expected from a single Landau Level in the low frequency limit, quantized in units of the fine structure constant. At 8 T, the plateau extends over a range of gate voltage that spans an electron density greater than 14 times the quantum flux density. Both the imaginary part of the Faraday angle and transmission measurements indicate dissipative off-axis and longitudinal conductivity channels associated with the plateau.

5 pages, 2 figures

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Cited by in corpus (5)

• Emergence of decoupled surface transport channels in bulk insulating Bi2Se3 thin films
• Optical properties of magnetically doped ultra-thin topological insulator slabs
• Electromagnetic signatures of chiral quantum spin liquid
• The magneto-optical Faraday effect in spin liquid candidates
• Plasmon modes in the magnetically doped Single Layer and Multilayers of Helical Metals