RESONANT-TUNNELING IS DOUBLE-QUANTUM-WELL TRIPLE-BARRIER HETEROSTRUCTURES

We present a low-temperature (mK) magnetotransport study, using intens e pulsed magnetic fields to 50 T, of two double GaAs quantum well, tri ple A1As barrier resonant tunneling structures, which demonstrates the critical influence of the second quantum well on the tunneling behavi or. We show that charge accumulation in the first well, and thus the o verall tunneling characteristic, is controlled by the position of the lowest bound state in the second well, and identify tunneling transiti ons that are unique to triple-barrier structures. We also demonstrate that the tunneling current is sensitive to integer and fractional quan tum Hall effect states, and find that the voltage-tunable accumulation of charge in one of the samples provides an unusual environment for t he study of ground states of a two-dimensional electron system.