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arXiv · 2403.13595

General criterion for non-Hermitian skin effects and Application: Fock space skin effects in many body systems

Kenji Shimomura·Masatoshi Sato
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Abstract

Non-Hermiticity enables macroscopic accumulation of bulk states, named non-Hermitian skin effects. The non-Hermitian skin effects are well-established for single-particle systems, but their proper characterization for general systems is elusive. Here, we propose a general criterion of non-Hermitian skin effects, which works for any finite-dimensional system evolved by a linear operator. The applicable systems include many-body systems and network systems. A system meeting the criterion exhibits enhanced non-normality of the evolution operator, accompanied by exceptional characteristics intrinsic to non-Hermitian systems. Applying the criterion, we discover a new type of non-Hermitian skin effect in many-body systems, which we dub the Fock space skin effect. We also discuss the Fock space skin effect-induced slow dynamics, which gives an experimental signal for the Fock space skin effect.

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Kenji Shimomura, Masatoshi Sato. 2024-03-20. General criterion for non-Hermitian skin effects and Application: Fock space skin effects in many body systems. https://doi.org/10.1103/physrevlett.133.136502

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