Compare Papers
Paper 1
Procedure via cross-Kerr nonlinearities for encoding single logical qubit information onto four-photon decoherence-free states.
Heo J, Choi SG.
- Year
- 2021
- Journal
- Sci Rep
- DOI
- 10.1038/s41598-021-89809-w
- arXiv
- -
No abstract.
Open paperPaper 2
Non-Hermitian spectral flows and Berry-Chern monopoles
Lucien Jezequel, Pierre Delplace
- Year
- 2022
- Journal
- arXiv preprint
- DOI
- arXiv:2209.03876
- arXiv
- 2209.03876
We propose a non-Hermitian generalization of the correspondence between the spectral flow and the topological charges of band crossing points (Berry-Chern monopoles). A class of non-Hermitian Hamiltonians that display a complex-valued spectral flow is built by deforming an Hermitian model while preserving its analytical index. We relate those spectral flows to a generalized Chern number that we show to be equal to that of the Hermitian case, provided a line gap exists. We demonstrate the homotopic invariance of both the non-Hermitian Chern number and the spectral flow index, making explicit their topological nature. In the absence of a line gap, our system still displays a spectral flow whose topology can be captured by exploiting an emergent pseudo-Hermitian symmetry.
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