Onset voltage shift due to nonzero Landau ground-state level in coherent magnetotransport

Abstract

Coherent electron transport in double-barrier heterostructures with parallel electric and magnetic fields is analyzed theoretically and with the aid of a quantum simulator accounting for three-dimensional transport effects. The onset-voltage shift induced by the magnetic field in resonant tunneling diodes, which was previously attributed to the cyclotron frequency ${w}_{c}$ inside the well is found to arise from an upward shift of the nonzero ground (lowest) Landau state energy in the entire quantum region where coherent transport takes place. The spatial dependence of the cyclotron frequency is accounted for and verified to have a negligible impact on resonant tunneling for the device and magnetic field strength considered. A correction term for the onset-voltage shift arising from the magnetic field dependence of the chemical potential is also derived. The Landau ground state with its nonvanishing finite harmonic oscillator energy $\ensuremath{\Elzxh}{w}_{c}/2$ is verified, however, to be the principal contributor to the onset voltage shift at low temperatures.