Suppression of dephasing and phase lapses in the fractional quantum Hall regime

Abstract

A charge fluctuator which is electrostatically coupled to a conducting channel may fully dephase quantum transport through the latter. Here, we address the case where a quantum dot (QD), playing the role of a charge fluctuator, is tunnel-coupled to an additional channel. In the case where the latter may support fractional charge, distinct differences from the integer case arise: Abrupt phase lapses of the transmission through the conducting channel occur (which may or may not be equal to $\pi$). This is accompanied by a cusp-like suppression of the interferometer's visibility, yet no full dephasing. We interpret our findings in terms of the entanglement between the fluctuator and the conducting channels.

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References in corpus (6)

• Direct measurement of the coherence length of edge states in the Integer Quantum Hall Regime
• Finite bias visibility of the electronic Mach-Zehnder interferometer
• Decoherence and single electron charging in an electronic Mach-Zehnder interferometer
• Edge Channel Interference Controlled by Landau Level Filling
• Coherence oscillations in dephasing by non-Gaussian shot noise
• Quantum transport in electron Fabry-Perot interferometers