Transverse magnetic field studies in ${\mathrm{Al}}_{1\mathrm{-}\mathit{y}}$${\mathrm{In}}_{\mathit{y}}$As/${\mathrm{Ga}}_{1\mathrm{-}\mathit{x}}$${\mathrm{In}}_{\mathit{x}}$As quantum-well tunneling structures

We have studied the current-voltage (I-V) characteristics of a double-barrier, lattice-matched ${\mathrm{Ga}}_{1\mathrm{-}\mathit{x}}$ ${\mathrm{In}}_{\mathit{x}}$As/${\mathrm{Al}}_{1\mathrm{-}\mathit{y}}$ ${\mathrm{In}}_{\mathit{y}}$As tunneling structure in a transverse magnetic field, B, perpendicular to the current (B⊥J), in fields up to 18 T at temperatures <4.2 K. The devices used in this work showed stable dc I-V curves for all bias voltages and magnetic field values. This permitted the accurate determination of the bias-voltage position of the valley current and observation of the effect of B on the tunneling current in the negative-differential-resistance region. The data show the tunneling current turn-on and turn-off bias voltages behaving quadratically with B. We also observed the width of the resonance peak increasing linearly with B. All these observations are accurately explained by a simple description that accounts for the B-induced redistribution of the tunneling electron’s momentum and energy. A fit of this model to the data gives values of maxima in the transverse momentum that agree with values determined from magnetoquantum oscillations in the B∥J configuration on another device from the same wafer.