A5045117584- Topological Materials and Phenomena
- Quantum Mechanics and Non-Hermitian Physics
- Quantum chaos and dynamical systems
- Advanced Condensed Matter Physics
- Quantum many-body systems
- Quantum optics and atomic interactions
- Graphene research and applications
- Photonic and Optical Devices
- Atomic and Subatomic Physics Research
- Nonlinear Waves and Solitons
- Photonic Crystals and Applications
Nankai University
2021-2024
We predict novel topological phases with broken time-reversal symmetry supporting the coexistence of opposite chiral edge states, which are fundamentally different from photonic spin-Hall, valley-Hall, and higher-order phases. find a fine-grained categorization Chern insulators, their band topologies characterized by identical number completely different. Furthermore, we prove that cause zeros in Bloch wavefunction overlaps, imprint gap closing appear at degenerate points phase transition....
Topological edge states are the core of topological photonics. Here we introduce antihelical time-reversal symmetric metals and propose a photonic realization in an anisotropic square lattice coupled ring resonators, where clockwise counterclockwise modes play role pseudospins. The robustly propagate across corners toward diagonal lattice: same (opposite) pseudospins copropagate direction on parallel boundaries; different separate converge at opposite corners. metallic phase alter to helical...
Exceptional point and spectral singularity are two types of that unique to non-Hermitian systems. Here, we report the high-order as a pole scattering matrix for system, is unification exceptional singularity. At singularity, coefficients have divergence system stimulates lasing. The wave emission intensity polynomially enhanced, order growth in polynomial linearly scales with Furthermore, coherent input controls alters Our findings provide profound insights into fundamentals applications...
We study an anisotropic two-dimensional non-Hermitian Lieb lattice, where the staggered gain and loss present in horizontal vertical directions, respectively. The intra-cell nonreciprocal coupling generates magnetic flux enclosed unit cell of lattice creates nontrivial topology. active dissipative topological edge states are along also supports passive corner state. At appropriate flux, non-Hermiticity can alter state from one to opposite as increases. gapless phase is characterized by...
Topological metals possess gapless band structures accompanied with nontrivial edge states. are created from the topological insulators by adjusting magnetic flux. Here we propose time-reversal symmetry protected metal without employing metallic phase presents although Chern number vanishes. In topologically phase, three different cases in distinguished band-touching and in-gap features of These findings shed light on symmetric greatly simplify realization metals.
We predict novel topological phases with broken time-reversal symmetry supporting the coexistence of opposite chiral edge states, which are fundamentally different from photonic spin-Hall, valley-Hall, and higher-order phases. find a fine-grained categorization Chern insulators, their band topologies characterized by identical numbers completely different. Furthermore, we prove that cause zeros in Bloch wave function overlaps, imprint gap closing appear at degenerate points phase transition....