The g ‐factor of the conduction electrons in Bi 2 Se 3

The oscillatory part of the magneto‐resistance (Shubnikov‐de Haas effect) was investigated on n‐Bi 2 Se 3 single crystals with carrier concentrations between 5 × 10 17 and 1 × 10 18 cm −3 in the temperature range from 1.6 to 4.2 K in pulsed magnetic fields up to 35 T (350 kG) magnetic induction. Most experiments were performed for the magnetic induction B parallel to the trigonal axis c of the crystals, where the smallest cyclotron mass m c and a parabolic ε(κ) relation is present. No spin‐splitting of the Shubnikov‐de Haas resistivity extrema is observed at high quantum numbers. At low quantum numbers the influence of spin‐splitting causes a shift of the resistivity extrema and an additional maximum, which should not be present for M = gm c /(2 m 0 ) ≪ 1. A calculation of the magnetoresistance in quantizing magnetic fields based on Kubo's theory for a field‐independent carrier concentration enables the determination of the expression M = gm c /(2 m 0 ) = 2 with ±5% uncertainty for B ‖ c . The absolute value of the g ‐factor is evaluated hence as (32 ± 3) for B ‖ c . For arbitrary crystal orientation in the magnetic field M may be assumed to be constant within the error margin, the g ‐factor being consequently smaller for B ⟂ c : g ⟂ = (23 ± 3).