Anomalous Edge State in a Non-Hermitian Lattice.

By Tony E. Lee. Physical Review Letters, 2016

834 citations recorded by the source corpus.

We show that the bulk-boundary correspondence for topological insulators can be modified in the presence of non-Hermiticity. We consider a one-dimensional tight-binding model with gain and loss as well as long-range hopping. The system is described by a non-Hermitian Hamiltonian that encircles an exceptional point in momentum space. The winding number has a fractional value of 1/2. There is only one dynamically stable zero-energy edge state due to the defectiveness of the Hamiltonian. This edge state is robust to disorder due to protection by a chiral symmetry. We also discuss experimental realization with arrays of coupled resonator optical waveguides.

Subfields: Atomic and Molecular Physics, and Optics, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/dcc2e0d84ebe499f9a3d3be50a31a278b0acfaa9

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In Atomic and Molecular Physics, and Optics

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Citations in the corpus

Edge Modes, Degeneracies, and Topological Numbers in Non-Hermitian Systems. (2016, background): “Previous researchers [11, 12, 16, 38] have focused on the winding numbers of the eigenvectors ψ±.”
Interplay of non-Hermitian skin effects and Anderson localization in nonreciprocal quasiperiodic lattices (2019, background): “[43] Tony E.”
Non-Hermitian Chern Bands. (2018, positive): “The dissimilarity between open-boundary and Bloch spectra has also been found in a 1D model [46,53,54,56], whose spectra can be readily obtained via a similarity transformation to a Hermitian Hamiltonian [56].”
Probing non-Hermitian skin effect and non-Bloch phase transitions (2019, methodology): “Topological characterization of non-Hermitian models is currently a hot area of research (see [4–14] and references therein).”
Non-Bloch band theory of non-Hermitian Hamiltonians in the symplectic class (2020, methodology): “Reference [20] numerically investigated a non-Hermitian extension of the Su-Schrieffer-Heeger model [3] with asymmetric hopping, which is a prototypical example that exhibits the nonHermitian skin effect.”
Reciprocal skin effect and its realization in a topolectrical circuit (2019, background): “[12] T.”
Complex Spacing Ratios: A Signature of Dissipative Quantum Chaos (2019, background): “[22] T.”