Non-Hermitian topology in a multi-terminal quantum Hall device

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Kyrylo Ochkan - , Leibniz Institute for Solid State and Materials Research Dresden, Würzburg-Dresden Cluster of Excellence ct.qmat (Author)
  • Raghav Chaturvedi - , Leibniz Institute for Solid State and Materials Research Dresden, Würzburg-Dresden Cluster of Excellence ct.qmat (Author)
  • Viktor Könye - , Leibniz Institute for Solid State and Materials Research Dresden, Würzburg-Dresden Cluster of Excellence ct.qmat (Author)
  • Louis Veyrat - , Leibniz Institute for Solid State and Materials Research Dresden, Würzburg-Dresden Cluster of Excellence ct.qmat (Author)
  • Romain Giraud - , Leibniz Institute for Solid State and Materials Research Dresden, Université Grenoble Alpes (Author)
  • Dominique Mailly - , Université Paris-Saclay (Author)
  • Antonella Cavanna - , Université Paris-Saclay (Author)
  • Ulf Gennser - , Université Paris-Saclay (Author)
  • Ewelina M. Hankiewicz - , Würzburg-Dresden Cluster of Excellence ct.qmat, University of Würzburg (Author)
  • Bernd Büchner - , Clusters of Excellence ct.qmat: Complexity and Topology in Quantum Matter, Chair of Experimental Solid State Physics, Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • Jeroen van den Brink - , Clusters of Excellence ct.qmat: Complexity and Topology in Quantum Matter, Chair of Solid State Theory, Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • Joseph Dufouleur - , Leibniz Institute for Solid State and Materials Research Dresden, Würzburg-Dresden Cluster of Excellence ct.qmat (Author)
  • Ion Cosma Fulga - , Leibniz Institute for Solid State and Materials Research Dresden, Würzburg-Dresden Cluster of Excellence ct.qmat (Author)

Abstract

Quantum devices characterized by non-Hermitian topology are predicted to show highly robust and potentially useful properties for precision sensing and signal amplification. However, realizing them has remained a daunting experimental task, as non-Hermiticity is often associated with gain and loss, which would require precise tailoring to produce the signatures of non-trivial topology. Here, instead of gain and loss, we use the non-reciprocity of 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, characterized by currents and voltages showing an exponential profile that persists 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.

Details

Original languageEnglish
Pages (from-to)395-401
Number of pages7
JournalNature physics
Volume20
Issue number3
Early online date18 Jan 2024
Publication statusPublished - Mar 2024
Peer-reviewedYes

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