Conduction-band structure ofBi2−xSbxSe

Fanoq-reversal in topological insulator Bi2Se3

“…3(a) with open squares. These recently reported values are in general agreement with earlier reports from optical and quantum oscillations measurements [22,23,24].…”

Magneto-optical and magnetoelectric effects of topological insulators in quantizing magnetic fields

“…Faraday's and Ampère's Laws then imply that the electric field is spatially constant across the film, while the magnetic field jumps by a value proportional to the current integrated across the TI film. Allowing for a bulk conductivity Σ due to unintended doping [3] and assuming a small bulk Hall angle we find that the low-frequency quantum-Hallregime Faraday and Kerr angles depend on the TI surface properties only through ν T + ν B :…”

“…When the product of the bulk conductivity and the film thickness in e 2 /h units is small compared to α, magneto-optical properties are only weakly dependent on accidental doping in the interior of the film. Our work is motivated in part by potential advantages of magneto-optical over transport [3] characterization in isolating TI surface properties from bulk contamination due to unintended doping. Since Landau level (LL) quantization of the TI's surface Dirac cones has recently been established by STM experiments [4], it should be possible to detect surface quantum Hall effects optically, even when parallel bulk conduction is present.…”

Anomalous galvanomagnetism, cyclotron resonance, and microwave spectroscopy of topological insulators

“…It stems from dissipative bulk conductivity which generally cannot be ignored because of the complex band structure of three-dimensional TI where the Fermi level does not necessarily lie in the bulk band gap or crosses both the surface and bulk states. [14][15][16][17] For a TI film with thickness d, bulk zero-field dc conductivity Σ and surface QH conductivity σ H ∼ e 2 /h, the contribution of the surface with respect to the bulk is characterized by parameter e 2 /hdΣ. 10 It has been shown that the well-resolved surface magneto-electric effects, such as the Kerr or Faraday rotation, require sufficiently large values of e 2 /hdΣ.…”