Re-entrant resonant tunneling

Abstract

We study the effect of electron-electron interactions on the resonant-tunneling spectroscopy of the localized states in a barrier. Using a simple model of three localized states, we show that, due to the Coulomb interactions, a single state can give rise to two resonant peaks in the conductance as a function of gate voltage, G(Vg). We also demonstrate that an additional higher-order resonance with Vg-position in between these two peaks becomes possibile when interactions are taken into account. The corresponding resonant-tunneling process involves two-electron transitions. We have observed both these effects in GaAs transistor microstructures by studying the time evolution of three adjacent G(Vg) peaks caused by fluctuating occupation of an isolated impurity (modulator). The heights of the two stronger peaks exibit in-phase fluctuations. The phase of fluctuations of the smaller middle peak is opposite. The two stronger peaks have their origin in the same localized state, and the third one corresponds to a co-tunneling process.

9 pages, REVTeX, 4 figures

Cited by in corpus (7)

• Coherent and Collective Quantum Optical Effects in Mesoscopic Systems
• Current Switch by Coherent Trapping of Electrons in Quantum Dots
• Coulomb Blockade in low mobility nanometer size Si:MOSFETs
• Theory of charge sensing in quantum-dot structures
• Mesoscopic Behavior Near a Two-Dimensional Metal-Insulator Transition
• Non-local coupling of two donor-bound electrons
• Regimes of correlated hopping via a two-site interacting chain