Conduction-bandgfactor anisotropy in indium antimonide

The effective mass Hamiltonian for the conduction band of indium antimonide in a magnetic field is extended to include terms of up to fourth order in [ K over bar], the modified wave vector. The energy corrections provided by the additional terms are evaluated using perturbation theory. An anisotropic correction to the effective g value is found which, at magnetic field strengths of 100 kG, produces a variation of about 3% in g within the first Landau level. The correction increases with field strength and with Landau level number, and is a maximum with the field oriented along a (111) direction, and zero with the field along a (100) direction. Isotropic corrections to g are also found together with isotropic and anisotropic corrections to the effective mass.