The g‐Factor of the Holes in the Highest Valence Band of Bi2Te3

Abstract

AbstractThe Shubnikov‐de Haas effect is investigated on p‐type Bi2Te3 in the concentration range from 5 × 1017 to 1.1 × 1019 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 = gmc/(2m0) 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 mc, 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 ϑo = 31.5° ± 10% (ϑ0 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 ϑ0 relative to the bisectrix axis) are of about one order of magnitude larger than g′3 ≈ 2 (within the regarded mirror plane, tilted by ϑ0 relative to the trigonal axis). The results correspond to the data of the lowest conduction band of Bi2Te3 in every respect, and are discussed qualitatively in a six‐band model.