Observation of non-Hermitian topology in a multi-terminal quantum Hall device
Abstract
Quantum devices characterized by non-Hermitian topology are predicted to show highly robust and potentially useful properties, but realizing them has remained a daunting experimental task. This is because non-Hermiticity is often associated with gain and loss, which would require precise tailoring to produce the signatures of nontrivial topology. Here, instead of gain/loss, we use the nonreciprocity of the quantum Hall edge states to directly observe non-Hermitian topology in a multi-terminal quantum Hall ring. Our transport measurements evidence a robust, non-Hermitian skin effect: currents and voltages show an exponential profile, which persists also across Hall plateau transitions away from the regime of maximum non-reciprocity. Our observation of non-Hermitian topology in a quantum device introduces a scalable experimental approach to construct and investigate generic non-Hermitian systems.
Keywords
Cite
@article{arxiv.2305.18674,
title = {Observation of non-Hermitian topology in a multi-terminal quantum Hall device},
author = {Kyrylo Ochkan and Raghav Chaturvedi and Viktor Könye and Louis Veyrat and Romain Giraud and Dominique Mailly and Antonella Cavanna and Ulf Gennser and Ewelina M. Hankiewicz and Bernd Büchner and Jeroen van den Brink and Joseph Dufouleur and Ion Cosma Fulga},
journal= {arXiv preprint arXiv:2305.18674},
year = {2024}
}