The Quantum Variation of Fermi Energy in Bismuth under High Magnetic Fields

Abstract

Alfven wave transmission through bismuth single crystals is measured using 50 Gc microwave interferometer under pulsed magnetic field up to 200 kG at liquid helium temperatures. It is found that the mass densities change remarkably with magnetic field for all cases studied. These changes are ascribed to the quantum variation of Fermi energy at high magnetic field. The shifts of Fermi energy are determined as a function of magnetic field assuming the nonparabolic band for holes. From the analysis based on the Baraff’s theory, it is found that the lowest Landau levels of light electrons go down linearly with magnetic field instead of the parabolic change expected from the modified two band model.
It is also found that the lattice dielectric constant has an anisotropy. If ε_⊥\doteqdot100 is adopted according to Boyle and Brailsford, we obtain ε_⁄⁄\doteqdot60 in the present experiments, where ε_⁄⁄ and ε_⊥ are the dielectric constants for waves polarized along and perpendicular to the trigonal axis, respectively.