The g ‐Factor of the Holes in the Highest Valence Band of Bi 2 Te 3

The Shubnikov‐de Haas effect is investigated on p‐type Bi 2 Te 3 in the concentration range from 5 × 10 17 to 1.1 × 10 19 cm −3 , in magnetic fields up to 10 T flux density, between 1.6 and 4.2 K. From spin‐splitting of the magnetoresistance maxima the product M = gm c /(2 m 0 ) is found to be strongly anisotropic in contrast to the results on other semiconductors. Hence the g ‐factors may be determined, by inserting the known cyclotron masses m c , yielding a considerable energy dependence and anisotropy of the second rank tensor components of g . From values for | M | ≷ 1 a positive sign for the g ‐factor ( g > 0) is deduced. Assuming ϑ o = 31.5° ± 10% (ϑ 0 tilt angle of ellipsoidal principal axes of the Fermi surfaces relative to the crystal axes) to fit also to the corresponding g ‐tensor ellipsoids, the principal values g ′ 1 (parallel to the binary axis) and g ′ 2 (in the mirror plane, tilted by ϑ 0 relative to the bisectrix axis) are of about one order of magnitude larger than g ′ 3 ≈ 2 (within the regarded mirror plane, tilted by ϑ 0 relative to the trigonal axis). The results correspond to the data of the lowest conduction band of Bi 2 Te 3 in every respect, and are discussed qualitatively in a six‐band model.