Observation of the non-Hermitian Skin effect in topolectric circuits

ORAL

Abstract

A contemporary frontier of metamaterial research is the challenge non-Hermitian systems pose to the established characterization of topological matter. There, one of the most relied upon principles is the bulk-boundary correspondence (BBC): energy eigenvalues and eigenstates exhibit a perturbatively small change as the boundary conditions are modified from periodic to open by changing a single bond. The framework of BBC captures the emergence of protected surface states at the boundary of a system with non-trivial bulk topology. In this talk, we present a periodic circuit network, where gain and loss conspire with the violation of reciprocity to affect this principle dramatically. Switching from periodic to open boundary conditions results in a non-perturbative change of all eigenmodes in this system. We experimentally observe the non-Hermitian Skin effect with extensive mode localization at open boundaries for the first time.

Reference: T. Helbig, et al. arXiv:1907.11562 (2019).

*Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) through Project-ID 258499086 - SFB 1170 and through the Wuerzburg-Dresden Cluster of Excellence on Complexity and Topology in Quantum Matter – ct.qmat Project-ID 39085490 - EXC 2147.

–

Presenters

  • Tobias Helbig

    • Theoretical physics I, University of Wuerzburg
    • Institute for Theoretical Physics and Astrophysics, University of Wurzburg
    • University of Wurzburg

Authors

  • Tobias Helbig

    • Theoretical physics I, University of Wuerzburg
    • Institute for Theoretical Physics and Astrophysics, University of Wurzburg
    • University of Wurzburg

  • Tobias Hofmann

    • Theoretical physics I, University of Wuerzburg
    • Institute for Theoretical Physics and Astrophysics, University of Wurzburg
    • University of Wurzburg

  • Ching Hua Lee

    • Department of Physics, National University of Singapore
    • National University of Singapore

  • Martin Greiter

    • Institute for Theoretical Physics and Astrophysics, University of Wurzburg
    • University of Wurzburg

  • Ronny Thomale

    • University of Wurzburg
    • Institute for Theoretical Physics, University of Wuerzburg
    • Theoretical physics I, University of Wuerzburg
    • University of Wuerzburg
    • Institut für Theoretische Physik und Astrophysik, Universität Würzburg
    • Physics department, University of Wuerzburg
    • Institut für Theoretische Physik und Astrophysik, University of Würzburg
    • Institute for Theoretical Physics and Astrophysics, University of Wurzburg