Topological phases and their associated multiple edge states are studied by constructing a one-dimensional non-unitary multi-period quantum walk with parity-time symmetry.It is shown that large topological numbers can...Topological phases and their associated multiple edge states are studied by constructing a one-dimensional non-unitary multi-period quantum walk with parity-time symmetry.It is shown that large topological numbers can be obtained when choosing an appropriate time frame.The maximum value of the winding number can reach the number of periods in the one-step evolution operator.The validity of the bulk-edge correspondence is confirmed,while for an odd-period quantum walk and an even-period quantum walk,they have different configurations of the 0-energy edge state andπ-energy edge state.On the boundary,two kinds of edge states always coexist in equal amount for the odd-period quantum walk,however three cases including equal amount,unequal amount or even only one type may occur for the even-period quantum walk.展开更多
Hybrid metal-dielectric structures combine the advantages of both metal and dielectric materials,enabling high-confined but low-loss magnetic and electric resonances through deliberate arrangements.However,their poten...Hybrid metal-dielectric structures combine the advantages of both metal and dielectric materials,enabling high-confined but low-loss magnetic and electric resonances through deliberate arrangements.However,their potential for enhancing magnetic emission has yet to be fully explored.Here,we study the magnetic and electric Purcell enhancement supported by a hybrid structure composed of a dielectric nanoring and a silver nanorod.This structure enables low Ohmic loss and highlyconfined field under the mode hybridization of magnetic resonances on a nanoring and electric resonances on a nanorod in the optical communication band.Thus,the 60-fold magnetic Purcell enhancement and 45-fold electric Purcell enhancement can be achieved.Over 90%of the radiation can be transmitted to the far field.For the sufficiently large Purcell enhancement,the position of emitter has a tolerance of several tens of nanometers,which brings convenience to experimental fabrications.Moreover,an array formed by this hybrid nanostructure can further enhance the magnetic Purcell factors.The system provides a feasible option to selectively excite magnetic and electric emission in integrated photonic circuits.It may also facilitate brighter magnetic emission sources and light-emitting metasurfaces with a more straightforward design.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.12004231).
文摘Topological phases and their associated multiple edge states are studied by constructing a one-dimensional non-unitary multi-period quantum walk with parity-time symmetry.It is shown that large topological numbers can be obtained when choosing an appropriate time frame.The maximum value of the winding number can reach the number of periods in the one-step evolution operator.The validity of the bulk-edge correspondence is confirmed,while for an odd-period quantum walk and an even-period quantum walk,they have different configurations of the 0-energy edge state andπ-energy edge state.On the boundary,two kinds of edge states always coexist in equal amount for the odd-period quantum walk,however three cases including equal amount,unequal amount or even only one type may occur for the even-period quantum walk.
基金supported by the National Natural Science Foundation of China(Nos.11974032,11734001,and 11525414)the Key R&D Program of Guangdong Province(No.2018B030329001).
文摘Hybrid metal-dielectric structures combine the advantages of both metal and dielectric materials,enabling high-confined but low-loss magnetic and electric resonances through deliberate arrangements.However,their potential for enhancing magnetic emission has yet to be fully explored.Here,we study the magnetic and electric Purcell enhancement supported by a hybrid structure composed of a dielectric nanoring and a silver nanorod.This structure enables low Ohmic loss and highlyconfined field under the mode hybridization of magnetic resonances on a nanoring and electric resonances on a nanorod in the optical communication band.Thus,the 60-fold magnetic Purcell enhancement and 45-fold electric Purcell enhancement can be achieved.Over 90%of the radiation can be transmitted to the far field.For the sufficiently large Purcell enhancement,the position of emitter has a tolerance of several tens of nanometers,which brings convenience to experimental fabrications.Moreover,an array formed by this hybrid nanostructure can further enhance the magnetic Purcell factors.The system provides a feasible option to selectively excite magnetic and electric emission in integrated photonic circuits.It may also facilitate brighter magnetic emission sources and light-emitting metasurfaces with a more straightforward design.
