Unambiguous determination of the g factor for holes in bismuth at high B / T

Magnetotransport has been investigated in high-purity bismuth crystals in static magnetic fields as high as 20 T and temperatures as low as 25 mK. This high B/T ratio permits observation of pronounced Shubnikov--de Haas oscillations over a wide field range and up to fields where most of the carriers are in the lowest Landau level. For transport currents in the bisectrix or binary directions, and field in the perpendicular trigonal direction, we have observed doublet splittings centered on each Shubnikov--de Haas oscillation. These splittings exhibit a quadratic dependence on field and disappear before the last oscillation. Our observations allow us to conclude unambiguously that when the Landau-level index is as high as 2, the carriers are fully polarized and the g factor for holes with the field in the trigonal direction is 35.3(4).