non-Hermitian chainstopological phase transitionsThe contents of topological classification of matter are enriched by non-Hermiticity, such as exceptional points, bulk-edge correspondence, and skin effects. Physically, gain and loss can be introduced by imaginary on-site potentials of lattice Hamiltonians...
报告题目 Floquet Topological Phases of Non-Hermitian Systems 报告时间 2020-07-02 00:00 报告地点 线上 报告摘要 The non-Hermiticity caused breakdown of the bulk-boundary correspondence (BBC) in topological phase transition was curled by the skin effect for the systems with chiral symmetry and transl...
Recently, optical nonlinearity has emerged as a tool for tailoring topological and non-Hermitian (NH) properties, promising fast manipulation of topological phases. In this work, we observe topologically protected NH phase transitions driven by optical nonlinearity in a silicon nanophotonic Floquet ...
We study topological phases of a non-Hermitian coupled Su–Schrieffer–Heeger(SSH) ladder. The model originates from the brick-wall lattices in the two-row limit. The Hamiltonian can be brought into block off-diagonal form and the winding number can be defined with the determine of the block...
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non‐Hermitian topological phase transitionsThe topological properties of a generalized non〩ermitian Su–Schrieffer–Heeger model are investigated and it is demonstrated that the non〩ermitian phase transition and the non〩ermitian skin effect can be induced by intraヽell asymmetric coupling under open...
Different from the Hermitian case, the transition generically involves an extended intermediate phase with complex-energy band degeneracies at isolated "exceptional points" in momentum space. We also systematically classify all types of band degeneracies. 展开 ...
Furthermore, based on the Wilson loop calculation, the topology of the PT-symmetric system in the PT exact phase is demonstrated to keep unchanged as the Hermitian system. At last, different kinds of edge states in Hermitian systems under the influences of gain and loss are studied and we ...
It was later discovered that the existence of the topological invariant (non-zero Chern number) is the root cause of quantization, which is independent of symmetry breaking [2]. If the Chern number is zero, the phase of the structure is ordinary; otherwise, it is topological. The Chern ...
When the two chains have identical hopping but are off-set by one lattice site, the topological phase of the SSH ladder is characterized by the existence of Dirac zero energy modes at the edge. These modes are similar to the Majorana modes of the Kitaev chain with respect to the spatial ...