Anomalous Behavior of the Non-Hermitian Topological System with an Asymmetric Coupling Impurity
A notable feature of systems with non-Hermitian skin effects is the sensitivity to boundary conditions. In this work, we introduce one type of boundary condition provided by a coupling impurity. We consider a system where a two-level system as an impurity couples to a nonreciprocal Su–Schrieffer–Hee...
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-01-01
|
| Series: | Entropy |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1099-4300/27/1/78 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1832588546039349248 |
|---|---|
| author | Junjie Wang Fude Li Weijun Cheng |
| author_facet | Junjie Wang Fude Li Weijun Cheng |
| author_sort | Junjie Wang |
| collection | DOAJ |
| description | A notable feature of systems with non-Hermitian skin effects is the sensitivity to boundary conditions. In this work, we introduce one type of boundary condition provided by a coupling impurity. We consider a system where a two-level system as an impurity couples to a nonreciprocal Su–Schrieffer–Heeger chain under periodic boundary conditions at two points with asymmetric couplings. We first study the spectrum of the system and find that asymmetric couplings lead to topological phase transitions. Meanwhile, a striking feature is that the coupling impurity can act as an effective boundary, and asymmetric couplings can also induce a flexibly adjusted zero mode. It is localized at one of the two effective boundaries or both of them by tuning coupling strengths. Moreover, we uncover three types of localization behaviors of eigenstates for this non-Hermitian impurity system with on-site disorder. These results corroborate the potential for control of a class of non-Hermitian systems with coupling impurities. |
| format | Article |
| id | doaj-art-433884f0277c410aaa5193974e64abf4 |
| institution | Kabale University |
| issn | 1099-4300 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Entropy |
| spelling | doaj-art-433884f0277c410aaa5193974e64abf42025-01-24T13:31:55ZengMDPI AGEntropy1099-43002025-01-012717810.3390/e27010078Anomalous Behavior of the Non-Hermitian Topological System with an Asymmetric Coupling ImpurityJunjie Wang0Fude Li1Weijun Cheng2College of Digital Technology and Engineering, Ningbo University of Finance & Economics, Ningbo 315175, ChinaCollege of Computer and Information Engineering, Tianjin Agricultural University, Tianjin 300384, ChinaSchool of Integrated Circuits, Tsinghua University, Beijing 100084, ChinaA notable feature of systems with non-Hermitian skin effects is the sensitivity to boundary conditions. In this work, we introduce one type of boundary condition provided by a coupling impurity. We consider a system where a two-level system as an impurity couples to a nonreciprocal Su–Schrieffer–Heeger chain under periodic boundary conditions at two points with asymmetric couplings. We first study the spectrum of the system and find that asymmetric couplings lead to topological phase transitions. Meanwhile, a striking feature is that the coupling impurity can act as an effective boundary, and asymmetric couplings can also induce a flexibly adjusted zero mode. It is localized at one of the two effective boundaries or both of them by tuning coupling strengths. Moreover, we uncover three types of localization behaviors of eigenstates for this non-Hermitian impurity system with on-site disorder. These results corroborate the potential for control of a class of non-Hermitian systems with coupling impurities.https://www.mdpi.com/1099-4300/27/1/78impuritynon-Hermitian systemquantum phase transition |
| spellingShingle | Junjie Wang Fude Li Weijun Cheng Anomalous Behavior of the Non-Hermitian Topological System with an Asymmetric Coupling Impurity Entropy impurity non-Hermitian system quantum phase transition |
| title | Anomalous Behavior of the Non-Hermitian Topological System with an Asymmetric Coupling Impurity |
| title_full | Anomalous Behavior of the Non-Hermitian Topological System with an Asymmetric Coupling Impurity |
| title_fullStr | Anomalous Behavior of the Non-Hermitian Topological System with an Asymmetric Coupling Impurity |
| title_full_unstemmed | Anomalous Behavior of the Non-Hermitian Topological System with an Asymmetric Coupling Impurity |
| title_short | Anomalous Behavior of the Non-Hermitian Topological System with an Asymmetric Coupling Impurity |
| title_sort | anomalous behavior of the non hermitian topological system with an asymmetric coupling impurity |
| topic | impurity non-Hermitian system quantum phase transition |
| url | https://www.mdpi.com/1099-4300/27/1/78 |
| work_keys_str_mv | AT junjiewang anomalousbehaviorofthenonhermitiantopologicalsystemwithanasymmetriccouplingimpurity AT fudeli anomalousbehaviorofthenonhermitiantopologicalsystemwithanasymmetriccouplingimpurity AT weijuncheng anomalousbehaviorofthenonhermitiantopologicalsystemwithanasymmetriccouplingimpurity |