THEORETICAL-STUDY OF MAGNETOTUNNELING SPECTROSCOPY

We present a quantum theory useful for analyzing the data of resonant magnetotunneling spectroscopy of semiconductor heterostructures. The e ffect of a vector potential on a tunneling electron, due to the magnet ic field, is described by using an in-plane wave vector that varies wi th traversal distance during the course of tunneling. We solve the eff ective-mass equation layer by layer, with the in-plane wave vector of electrons fixed in each layer. We calculate the tunneling current I as a function of bias V for various magnetic fields B, and, in agreement with recent experiments, find dramatic variations of peak currents wi th B, which is attributed to the coupling between heavy- and light-hol e states. We trace the voltages V-p at current peaks as functions of B , and compare them with the in-plane dispersion E(k(parallel to)), whi ch quantifies the relation between V-p(B) and E(k(parallel to)).