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arXiv · 2410.06160

Boundary-driven many-body phase transitions in a non-Hermitian disordered fermionic chain

Kuldeep Suthar
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Abstract

The non-Hermitian systems exhibit extreme sensitivity to the boundary conditions. The change in the eigenspectrum with tunning boundary parameter is intimately connected to the non-Hermitian skin effect. The single-particle systems are affected by the boundary perturbations; however the interplay of a random disorder potential and non-reciprocal hopping under boundary perturbations of an interacting many-body system is not yet clear. In this work, we examine the boundary sensitivity of a non-Hermitian interacting fermionic system in the presence of a random disorder potential. A non-zero boundary parameter results in real-complex spectral transitions with non-reciprocal (or unidirectional) hopping at weak disorder. While the many-body localization at strong disorder washes away real-complex transitions leading to dynamical stability and real eigenvalue spectrum. We show that the boundary-driven real-complex spectral transitions of the non-Hermitian chain are accompanied by the corresponding changes in the level statistics and nearest level-spacing distributions. The intriguing features of non-reciprocity and boundary sensitivity are further revealed using the averaged inverse participation ratios. Finally, we find distinct behaviour in the quench dynamics of local particle density, population imbalance, and entanglement entropy of charge-density-wave ordered state that corroborate the real-complex and localization transitions. Our results provide a route to understanding disordered many-body systems under a generalized boundary.

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BibTeXRIS

Kuldeep Suthar. 2024-10-08. Boundary-driven many-body phase transitions in a non-Hermitian disordered fermionic chain. https://doi.org/10.1103/physrevb.111.064202

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