Non-Hermitian boundary spectral winding

Ou，Zuxuan1; Wang，Yucheng2,3,4; Li，Linhu1

2023-04-15

10.1103/PhysRevB.107.L161404

Physical Review B   影响因子和分区

2469-9950

2469-9969

Spectral winding of complex eigenenergies represents a topological aspect unique in non-Hermitian systems, which vanishes in one-dimensional (1D) systems under the open boundary conditions (OBC). In this Letter, we discover a boundary spectral winding in two-dimensional non-Hermitian systems under the OBC, originating from the interplay between Hermitian boundary localization and non-Hermitian nonreciprocal pumping. Such a nontrivial boundary topology is demonstrated in a non-Hermitian breathing Kagome model with a triangle geometry, whose 1D boundary mimics a 1D non-Hermitian system under the periodic boundary conditions with nontrivial spectral winding. In a trapezoidal geometry, this boundary spectral winding can even coexist with corner accumulation of edge states, instead of extended ones along the 1D boundary of a triangle geometry. An OBC type of hybrid skin-topological effect may also emerge in a trapezoidal geometry, provided the boundary spectral winding completely vanishes. By studying the Green's function, we unveil that the boundary spectral winding can be detected from a topological response of the system to a local driving field, offering a realistic method to extract the nontrivial boundary topology for experimental studies.

SCI ; EI

英语

NI论文

其他

National Natural Science Foundation of China[12104519] ; Guangdong Basic and Applied Basic Research Foundation[2020A1515110773]

Materials Science ; Physics

Materials Science, Multidisciplinary ; Physics, Applied ; Physics, Condensed Matter

WOS:000970377800003

AMER PHYSICAL SOC

20231713949051

Boundary conditions ; Geometry ; Winding

Materials Handling Methods:691.2 ; Mathematics:921 ; Combinatorial Mathematics, Includes Graph Theory, Set Theory:921.4

PHYSICS

2-s2.0-85152940300

Scopus

1.Guangdong Provincial Key Laboratory of Quantum Metrology and Sensing,School of Physics and Astronomy,Sun Yat-Sen University,Zhuhai,Zhuhai Campus,519082,China
2.Shenzhen Institute for Quantum Science and Engineering,Southern University of Science and Technology,Shenzhen,518055,China
3.International Quantum Academy,Shenzhen,518048,China
4.Guangdong Provincial Key Laboratory of Quantum Science and Engineering,Southern University of Science and Technology,Shenzhen,518055,China

Ou，Zuxuan,Wang，Yucheng,Li，Linhu. Non-Hermitian boundary spectral winding[J]. Physical Review B,2023,107(16).

Ou，Zuxuan,Wang，Yucheng,&Li，Linhu.(2023).Non-Hermitian boundary spectral winding.Physical Review B,107(16).

Ou，Zuxuan,et al."Non-Hermitian boundary spectral winding".Physical Review B 107.16(2023).