Shimomura Kenji, Sato Masatoshi
Center for Gravitational Physics and Quantum Information, <a href="https://ror.org/0589kgd85">Yukawa Institute for Theoretical Physics</a>, Kyoto University, Kyoto 606-8502, Japan.
Phys Rev Lett. 2024 Sep 27;133(13):136502. doi: 10.1103/PhysRevLett.133.136502.
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.
非厄米性能够实现体态的宏观积累，即所谓的非厄米趋肤效应。非厄米趋肤效应在单粒子系统中已得到充分确立，但其在一般系统中的恰当表征却难以捉摸。在此，我们提出了一种非厄米趋肤效应的通用判据，该判据适用于由线性算符演化的任何有限维系统。适用的系统包括多体系统和网络系统。满足该判据的系统表现出演化算符增强的非正规性，并伴有非厄米系统固有的特殊性质。应用该判据，我们在多体系统中发现了一种新型的非厄米趋肤效应，我们将其称为福克空间趋肤效应。我们还讨论了福克空间趋肤效应引起的慢动力学，它给出了福克空间趋肤效应的一个实验信号。
