Edge Mode Engineering and Interferometry in the Quantum Hall Regime

The interference of fractional charges is a much sought after goal in a variety of electronic interferometers. It has been shown before in an electronic Mach-Zehnder interferometer that neutral modes, topological or non-topological (via edge-reconstruction), cause dephasing in the fractional quantum Hall effect regime [1]. Recently interference of fractional charges has been observed in an electronic Fabry-Perot interferometer [2], though anionic statistics was not revealed. Here, we have adapted a novel route of engineering edge channels away from the physical boundary in order to minimize edge reconstruction. First, we show that these engineered edge channels, especially fractional ones, can have different edge structures (with a different thermal conductance) compared to ubiquitous edge channels that have the same electrical conductance. We then used a modified Mach-Zehnder interferometer to interfere such synthetic edge modes, with initial promising results.


[1] Rajarshi Bhattacharyya, Mitali Banerjee, Moty Heiblum, Diana Mahalu, Vladimir Umansky, Phys. Rev. Lett. 122, 246801 (2019)
[2] J. Nakamura, S. Fallahi, H. Sahasrabuddhe, R. Rahman, S. Liang, G.C. Gardner, M.J. Manfra, Nature Physics 15, 563-569(2019)