Observation of Nonlinear Topological Corner States Originating from Different Spectral Charges
Abstract
AbstractHigher‐order topological insulators (HOTIs) are unique topological materials supporting edge states with the dimensionality at least by two lower than the dimensionality of the underlying structure. HOTIs are observed on lattices with different symmetries, but only in geometries, where truncation of HOTI produces a finite structure with the same order of discrete rotational symmetry as that of the unit cell, thereby setting the geometry of insulator edge. Here, a new type of 2D HOTI based on the Kekulé‐patterned lattice is experimentally demonstrated, whose order of discrete rotational symmetry differs from that of the unit cells of the constituent honeycomb lattice, with hybrid boundaries that help to produce all three possible corners that support effectively 0D corner states of topological origin, especially the one associated with spectral charge 5/6. It is also shown that linear corner states give rise to rich families of stable hybrid nonlinear corner states bifurcating from them in the presence of focusing nonlinearity of the material. Such new types of nonlinear corner states are observed in hybrid HOTI inscribed in transparent nonlinear dielectric using fs‐laser writing technique. The results complete the class of HOTIs and open the way to observation of topological states with new internal structure and symmetry.
Article Details
Authors (14)
Victor O. Kompanets
Institute of Spectroscopy Russian Academy of Sciences, Moscow Troitsk 108840 Russia
Suge Feng
Key Laboratory for Physical Electronics and Devices Ministry of Education School of Electronic Science and Engineering Xi'an Jiaotong University Xi'an 710049 China
Yiqi Zhang
Yaroslav V. Kartashov
Institute of Spectroscopy Russian Academy of Sciences, Moscow Troitsk 108840 Russia
Yongdong Li
Key Laboratory for Physical Electronics and Devices of the Ministry of Education, School of Electronic Science and Engineering, Xi’an Jiaotong University 1 , Xi’an 710049,
Sergei A. Zhuravitskii
Institute of Spectroscopy Russian Academy of Sciences, Moscow Troitsk 108840 Russia
Nikolay N. Skryabin
Institute of Spectroscopy Russian Academy of Sciences, Moscow Troitsk 108840 Russia
Alexander V. Kireev
Institute of Spectroscopy Russian Academy of Sciences, Moscow Troitsk 108840 Russia
Ivan V. Dyakonov
Quantum Technology Centre Faculty of Physics M. V. Lomonosov Moscow State University Moscow 119991 Russia
Alexander A. Kalinkin
Institute of Spectroscopy Russian Academy of Sciences, Moscow Troitsk 108840 Russia
Ce Shang
Sergei P. Kulik
Quantum Technology Centre Faculty of Physics M. V. Lomonosov Moscow State University Moscow 119991 Russia
Sergey V. Chekalin
Institute of Spectroscopy Russian Academy of Sciences, Moscow Troitsk 108840 Russia
Victor N. Zadkov
Institute of Spectroscopy Russian Academy of Sciences, Moscow Troitsk 108840 Russia