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arXiv · 0812.2612

Unexpected finite-bias visibility dependence in an electronic Mach Zehnder interferometer

E. Bieri·M. Weiss·O. Goktas·M. Hauser·S. Csonka·S. Oberholzer·C. Schonenberger
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Abstract

We use an electronic Mach-Zehnder interferometer to explore the non-equilibrium coherence of the electron waves within the edge-states that form in the integral quantum Hall effect. The visibility of the interference as a function of bias-voltage and transmission probabilities of the mirrors, which are realized by quantum point-contacts, reveal an unexpected asymmetry at finite bias when the transmission probability $T$ of the mirror at the input of the interferometer is varied between 0 and 100%, while the transmission probability of the other mirror at the output is kept fixed. This can lead to the surprising result of an increasing magnitude of interference with increasing bias-voltage for certain values of $T$. A detailed analysis for various transmission probabilities and different directions of the magnetic field demonstrates that this effect is not related to the transmission characteristics of a single quantum point contact, but is an inherent property of the Mach-Zehnder interferometer with edge-states.

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E. Bieri, M. Weiss, O. Goktas, M. Hauser, S. Csonka, S. Oberholzer, C. Schonenberger. 2008-12-14. Unexpected finite-bias visibility dependence in an electronic Mach Zehnder interferometer. https://doi.org/10.1103/physrevb.79.245324

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