TRANSVERSE MAGNETIC-FIELD STUDIES IN AL1-YINYAS GA1-XINXAS QUANTUM-WELL TUNNELING STRUCTURES

We have studied the current-voltage (I-V) characteristics of a double-barrier, lattice-matched Ga1-xInxAs/Al1-yInyAs tunneling structure in a transverse magnetic field, B, perpendicular to the current (BsJ), 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 electrones 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 BJ configuration on another device from the same wafer. © 1990 The American Physical Society.