Quantum coherence engineering in the integer quantum Hall regime

Abstract

We present an experiment where the quantum coherence in the edge states of the integer quantum Hall regime is tuned with a decoupling gate. The coherence length is determined by measuring the visibility of quantum interferences in a Mach-Zehnder interferometer as a function of temperature, in the quantum Hall regime at filling factor two. The temperature dependence of the coherence length can be varied by a factor of two. The strengthening of the phase coherence at finite temperature is shown to arise from a reduction of the coupling between co-propagating edge states. This opens the way for a strong improvement of the phase coherence of Quantum Hall systems. The decoupling gate also allows us to investigate how inter-edge state coupling influence the quantum interferences' dependence on the injection bias. We find that the finite bias visibility can be decomposed into two contributions: a Gaussian envelop which is surprisingly insensitive to the coupling, and a beating component which, on the contrary, is strongly affected by the coupling.

4 pages, 5 figures

References in corpus (9)

• Experimental realization of Wheeler's delayed-choice GedankenExperiment
• An On-Demand Coherent Single Electron Source
• Direct measurement of the coherence length of edge states in the Integer Quantum Hall Regime
• Dephasing in the electronic Mach-Zehnder interferometer at filling factor 2
• Finite bias visibility of the electronic Mach-Zehnder interferometer
• Tuning Energy Relaxation along Quantum Hall Channels
• Edge Channel Interference Controlled by Landau Level Filling
• Noise dephasing in the edge states of the Integer Quantum Hall regime
• Universality of Bias- and Temperature-induced Dephasing in Ballistic Electronic Interferometers

Cited by in corpus (6)

• Real time decoherence of Landau and Levitov quasi-particles in quantum Hall edge channels
• Mach-Zehnder interferometry with periodic voltage pulses
• Interference and multi-particle effects in a Mach-Zehnder interferometer with single-particle sources
• On-demand maximally entangled states with a parity meter and continuous feedback
• Equilibration in a chiral Luttinger liquid
• Decoherence of high-energy electrons in weakly disordered quantum Hall edge states