Oscillatory Tunneling between Quantum Hall Systems

TL;DR

This paper investigates electron tunneling between quantum Hall systems separated by a barrier, revealing conditions for oscillating tunneling currents driven by quantum effects, with implications for quantum device applications.

Contribution

It demonstrates that under certain conditions, electrons can tunnel continuously and oscillate between quantum Hall edge states without external drives, highlighting a novel quantum tunneling phenomenon.

Findings

Oscillating tunneling currents can occur without external drives.

Tunneling gaps influence the oscillation frequency and noise spectra.

Natural dephasing affects the coherence of tunneling currents.

Abstract

Electron tunneling between quantum Hall systems on the same two dimensional plane separated by a narrow barrier is studied. We show that in the limit where inelastic scattering time is much longer than the tunneling time, which can be achieved in practice, electrons can tunnel back and forth through the barrier continously, leading to an oscillating current in the absence of external drives. The oscillatory behavior is dictated by a tunneling gap in the energy spectrum. We shall discuss ways to generate oscillating currents and the phenomenon of natural ``dephasing" between the tunneling currents of edge states. The noise spectra of these junctions are also studied. They contain singularites reflecting the existence of tunneling gaps as well as the inherent oscillation in the system. (Figures will be given upon requests).