论文标题
非线性拓扑山谷大厅边缘态由II型狄拉克锥产生
Nonlinear Topological Valley Hall Edge States Arising from Type-II Dirac Cones
论文作者
论文摘要
II型DIRAC/WEYL点尽管在洛伦兹协方差引起的粒子物理学上不允许,但在凝聚的物理学中发现了基本兴趣和拓扑材料的有趣应用。最近,使用各种工程平台,包括光子晶体,波导阵列,元整日,磁化等离子体和北极星微柱,旨在朝着相对论量子仿真以及对外来拓扑现象的理解。但是,这种努力主要集中在真实或合成狄拉克/Weyl材料中的线性拓扑状态上。在这里,我们在激光写的各向异性光子晶格中演示了非线性谷霍尔边缘状态(VHESS),托有II型dirac点。这些自我捕获的VHESS表现为拓扑间隙准硅,从根本上与I型晶格中的线性对应物不同,并且与以前发现的所有拓扑孤子。我们的发现可能为理解洛伦兹(Lorentz)侵略性拓扑系统的非线性现象以及从拓扑绝缘体激光器开发高级光源的途径提供了一条途径。
Type-II Dirac/Weyl points, although impermissible in particle physics due to Lorentz covariance, were uncovered in condensed matter physics, driven by fundamental interest and intriguing applications of topological materials. Recently, there has been a surge of exploration of such generic points using various engineered platforms including photonic crystals, waveguide arrays, metasurfaces, magnetized plasma and polariton micropillars, aiming towards relativistic quantum emulation and understanding of exotic topological phenomena. Such endeavors, however, have focused mainly on linear topological states in real or synthetic Dirac/Weyl materials. Here, we demonstrate nonlinear valley Hall edge states (VHESs) in laser-writing anisotropic photonic lattices hosting type-II Dirac points. These self-trapped VHESs, manifested as topological gap quasi-solitons, are fundamentally distinct from their linear counterparts in type-I lattices and from all previously found topological solitons. Our finding may provide a route for understanding nonlinear phenomena in Lorentz-violating topological systems and for developing advanced light sources from topological insulator lasers.