The effect of magnetic fields up to 110 kOe on the reverse current in Sb-doped germanium tunnel diodes has been investigated. A marked reduction in the tunnel current with magnetic field is observed at reverse biases greater than that corresponding to the onset of direct band-to-band tunneling, which occurs at the Kane voltage $V_k$. This effect is essentially temperature-independent from 1.8 to 300°K except for a thermal broadening in the vicinity of $V_k$, and assumes a maximum value with H ⊥ I. In addition, at low temperature and for H∥I, small oscillations with both magnetic field and bias are observed in the tunnel current. For H∥I, a theoretical treatment based on the formation of Landau levels yields good agreement with both the observed shift in the current-voltage characteristic and the oscillatory component. For H ⊥ I, a phenomenological treatment based on conventional tunneling theory and on the assumption of a magnetic-field-dependent Kane voltage is in good agreement with experiment. Analysis of the data yields a shift in $V_k$ quadratic in the magnetic field, the constant of proportionality being ∼${10}^{-3\mathrm{}}$ mV/k${\mathrm{Oe}}^2$.

• Received 9 August 1965

DOI:https://doi.org/10.1103/PhysRev.145.667