Sequential Resonant Magnetotunneling through Landau Levels in GaAs/AlGaAs Multiple Quantum Well Structures

Abstract

We have investigated the tunneling current–voltage (I–V) characteristics of doped multiple quantum well (MQW) structures under high magnetic fields B. Strongly B-dependent periodic negative differential resistances (NDRs) have been observed in the first plateau-like region of the I–V characteristics and identified to be due to the sequential resonant tunneling through successive Landau levels. Furthermore, the observed voltage spacings of the NDRs are systematically smaller than the cyclotron energy. We have extended the theory developed by Kazarinov and Suris to a finite magnetic field case and found that all the observed features are well explained by the interplay between the scattering-assisted inter Landau-level tunneling and the B dependence of the two-dimensional electron supply function.