Higher-order topological insulators(HOTIs),with topological corner or hinge states,have emerged as a thriving topic in the field of topological physics.However,few connections have been found for HOTIs with well-explo...Higher-order topological insulators(HOTIs),with topological corner or hinge states,have emerged as a thriving topic in the field of topological physics.However,few connections have been found for HOTIs with well-explored first-order topological insulators.Recently a proposal asserted that a significant bridge can be established between the HOTIs and Z2 topological insulators.When subjected to an inplane Zeeman field,corner states,the signature of the HOTIs,can be induced in a Z2 topological insulator.Such Zeeman fields can be produced,for example,by the ferromagnetic proximity effect or magnetic atom doping,which drastically increases the experimental complexity.Here,we show that a phononic crystal,designed as a bilayer of coupled acoustic cavities,exactly hosts the Kane-Mele model with built-in in-plane Zeeman fields.The helical edge states along the zigzag edges are gapped,and the corner states,localized spatially at the corners of the samples,appear in the gap.This verifies the Zeeman field induced higher-order topology.We further demonstrate the intriguing contrast properties of the corner states at the outer and inner corners in a hexagonal ring-shaped sample.展开更多
Here, we propose a simple scheme to realize a one-dimensional （1D） modulated Rice-Mele model （RMM） and investigate its topological properties with a 1D circuit quantum electrodynamics （QED） lattice. The system c...Here, we propose a simple scheme to realize a one-dimensional （1D） modulated Rice-Mele model （RMM） and investigate its topological properties with a 1D circuit quantum electrodynamics （QED） lattice. The system can be mapped into a Chern insulator model by introducing a period parameter. Interestingly and surprisingly, we found that the circuit-QED lattice system always exhibits topologically nonttrvial phases if both the nearest-neighbor hopping strength between two resonators and the qubitassisted on-site potentials are alternately changed in the direction of the lattice. The numerical results show that the topological phases can be obtained by introducing an additional modulation parameter and both the edge state and topological invariant can be unambiguously seen with the existence of decay and disorders, even with few resonators in the lattice.展开更多
Higher-order topological phase in 2-dimensional(2D)systems is characterized by in-gap corner states,which are hard to detect and utilize.We numerically investigate transport properties of topological corner states in ...Higher-order topological phase in 2-dimensional(2D)systems is characterized by in-gap corner states,which are hard to detect and utilize.We numerically investigate transport properties of topological corner states in 2D honeycomb lattice,where the second-order topological phase is induced by an in-plane Zeeman field in the conventional Kane–Mele model.Through engineering multihollow structures with appropriate boundaries in honeycomb lattice,multiple corner states emerge,which greatly increases the probability to observe them.A typical two-probe setup is built to study the transport features of a diamond-shaped system with multihollow structures.Numerical results reveal the existence of global resonant states in bulk insulator,which corresponds to the resonant tunneling of multiple corner states and occupies the entire scattering region.Furthermore,based on the well separated energy levels of multiple corner states,a single-electron source is constructed.展开更多
基金supported by the National Natural Science Foundation of China(11890701,11974120,11974005,12074128,12074232,12125406,and 12174455)the National Key R&D Program of China(2018YFA0305800)+1 种基金the Guangdong Basic and Applied Basic Research Foundation(2019B151502012,2021B1515020086,and 2021A1515010347)the Science and Technology Projects in Guangzhou(202102020960)。
文摘Higher-order topological insulators(HOTIs),with topological corner or hinge states,have emerged as a thriving topic in the field of topological physics.However,few connections have been found for HOTIs with well-explored first-order topological insulators.Recently a proposal asserted that a significant bridge can be established between the HOTIs and Z2 topological insulators.When subjected to an inplane Zeeman field,corner states,the signature of the HOTIs,can be induced in a Z2 topological insulator.Such Zeeman fields can be produced,for example,by the ferromagnetic proximity effect or magnetic atom doping,which drastically increases the experimental complexity.Here,we show that a phononic crystal,designed as a bilayer of coupled acoustic cavities,exactly hosts the Kane-Mele model with built-in in-plane Zeeman fields.The helical edge states along the zigzag edges are gapped,and the corner states,localized spatially at the corners of the samples,appear in the gap.This verifies the Zeeman field induced higher-order topology.We further demonstrate the intriguing contrast properties of the corner states at the outer and inner corners in a hexagonal ring-shaped sample.
基金supported by the National Natural Science Foundation of China(Grant Nos.11465020,11264042,61465013,and 11564041)the Project of Jilin Science and Technology Development for Leading Talent of Science and Technology Innovation in Middle and Young and Team Project(Grant No.20160519022JH)
文摘Here, we propose a simple scheme to realize a one-dimensional （1D） modulated Rice-Mele model （RMM） and investigate its topological properties with a 1D circuit quantum electrodynamics （QED） lattice. The system can be mapped into a Chern insulator model by introducing a period parameter. Interestingly and surprisingly, we found that the circuit-QED lattice system always exhibits topologically nonttrvial phases if both the nearest-neighbor hopping strength between two resonators and the qubitassisted on-site potentials are alternately changed in the direction of the lattice. The numerical results show that the topological phases can be obtained by introducing an additional modulation parameter and both the edge state and topological invariant can be unambiguously seen with the existence of decay and disorders, even with few resonators in the lattice.
基金supported by the National Natural Science Foundation of China(Grant Nos.12174262 and 11774238)the Natural Science Foundation of Guangdong(Grant No.2020A1515011418)the Natural Science Foundation of Shenzhen(Grant Nos.20200812092737002,JCYJ20190808150409413,JCYJ20190808115415679,and JCYJ20190808152801642).
文摘Higher-order topological phase in 2-dimensional(2D)systems is characterized by in-gap corner states,which are hard to detect and utilize.We numerically investigate transport properties of topological corner states in 2D honeycomb lattice,where the second-order topological phase is induced by an in-plane Zeeman field in the conventional Kane–Mele model.Through engineering multihollow structures with appropriate boundaries in honeycomb lattice,multiple corner states emerge,which greatly increases the probability to observe them.A typical two-probe setup is built to study the transport features of a diamond-shaped system with multihollow structures.Numerical results reveal the existence of global resonant states in bulk insulator,which corresponds to the resonant tunneling of multiple corner states and occupies the entire scattering region.Furthermore,based on the well separated energy levels of multiple corner states,a single-electron source is constructed.
