Anisotropic size effects in bismuth-type semimetals

A theory of anisotropic size effects (ASE) in pure bulk single crystals of bismuth-type semimetals at helium temperatures in arbitrary magnetic fields is constructed. The model of three-electron and one-hole valley is used for deriving expressions for transverse quasi-Hall electric field, magnetoconductivity, magnetothermoelectric power of phonon drag, and transverse Nernst–Ettingshausen effect. Quantum oscillations of kinetic coefficients of semimetals induced by ASE are investigated. It is shown that the temperature dependence of the amplitude of these oscillations distinguishes them from the Shubnikov–de Haas and magnetophonon resonance oscillations. The oscillations of transverse magnetoresistance and longitudinal thermoelectric power of phonon drag in compensated materials are found to be giant.