Effective electron mass in ultrathin films of bismuth in the presence of crossed electric and quantizing magnetic fields

Abstract

The effective electron mass in ultrathin films of bismuth is studied in the presence of crossed electric and quantizing magnetic fields at low temperatures. Numerical results are presented for the McClure and Choi, hybrid, Cohen, Lax and ellipsoidal models by formulating the respective modified carrier energy spectra. It is found that the effective electron mass depends on the Fermi energy, Landau number and the electric sub-band index, owing to the inherent property of the cross field configuration, resulting in different effective masses corresponding to various sub-bands. The effective mass at the Fermi level increases with decreasing film thicknesses, increasing electron concentration and oscillates with the magnetic field. The quantum oscillations of the effective mass for the McClure and Choi model manifest themselves much more significantly than in other models.