Observation of bulk Landau levels in transverse magnetotunneling in Al_xGa_1-xAs capacitors

Two phenomena are observed for transverse magnetotunneling (B⊥J) from an accumulation layer in n- GaAs-undoped AlxGa1-xAs-n+ GaAs capacitors. One effect is a strong dependence of tunnel currents, J, at high applied voltage and high current densities, on the angle between J and the magnetic field, B. The second effect is the observation of structure in tunnel currents for applied voltages between 0.15 V and 0.6 V which is interpreted to result from tunneling into Landau levels formed in the n+ GaAs electrode. © 1987.