The Hall effect,discovered in 1879,requires magnetic fields or magnetic orders to produce a transverse voltage signal in response to the longitudinal driving electric field.However,the nonlinear Hall effect(NLHE),prop...The Hall effect,discovered in 1879,requires magnetic fields or magnetic orders to produce a transverse voltage signal in response to the longitudinal driving electric field.However,the nonlinear Hall effect(NLHE),proposed by Sodemann and Fu in 2015[1]has elucidated a novel Hall effect in time-reversal invariant and inversion-symmetry breaking materials featured with a nonlinear dependence on the primary current.展开更多
Exceptional points are degeneracies in the spectrum of non-Hermitian open systems where at least two eigenfrequencies and simultaneously the corresponding eigenstates of the Hamiltonian coalesce.Especially,the robust ...Exceptional points are degeneracies in the spectrum of non-Hermitian open systems where at least two eigenfrequencies and simultaneously the corresponding eigenstates of the Hamiltonian coalesce.Especially,the robust construction of higher-order exceptional points with more than two degenerate eigenfrequencies and eigenstates is challenging but yet worthwhile for applications.In this paper,we reconsider the formation of higher-order exceptional points through waveguide-coupled microring cavities and asymmetric backscattering.In this context,we demonstrate the influence of perturbations on the frequency splitting of the system.To generate higher-order exceptional points in a simple and robust way,a mirror-induced asymmetric backscattering approach is used.In addition to the exceptional-point enhanced sensing capabilities of such systems,also a cavity-selective sensitivity is achieved for particle sensing.The results are motivated by an effective Hamiltonian description and verified by full numerical simulations of the dielectric structure.展开更多
基金support from the Shenzhen Excellent Scientific and Technological Innovation Talent Training Program(RCBS20210609103859072)Shenzhen Institutions of Higher Learning Stability Support Plan(GXWD20231130102040001)+4 种基金the National Natural Science Foundation of China(62105081)support from the National Natural Science Foundation of China(62174044)support from the DFG(SFB1170)the Würzburg-Dresden Cluster of Excellence ct.qmat,EXC2147,Project ID 390858490the Bavarian Ministry of Economic Affairs,Regional Development and Energy within the High Tech Agenda Project‘‘Bausteine für das Quanten Computing auf Basis Topologischer Materialen”。
文摘The Hall effect,discovered in 1879,requires magnetic fields or magnetic orders to produce a transverse voltage signal in response to the longitudinal driving electric field.However,the nonlinear Hall effect(NLHE),proposed by Sodemann and Fu in 2015[1]has elucidated a novel Hall effect in time-reversal invariant and inversion-symmetry breaking materials featured with a nonlinear dependence on the primary current.
基金Deutsche Forschungsgemeinschaft(EXC 2147,Project ID 390858490,KL 3124/6-1,WI 1986/14-1)Open Access Publication Fund of Magdeburg University。
文摘Exceptional points are degeneracies in the spectrum of non-Hermitian open systems where at least two eigenfrequencies and simultaneously the corresponding eigenstates of the Hamiltonian coalesce.Especially,the robust construction of higher-order exceptional points with more than two degenerate eigenfrequencies and eigenstates is challenging but yet worthwhile for applications.In this paper,we reconsider the formation of higher-order exceptional points through waveguide-coupled microring cavities and asymmetric backscattering.In this context,we demonstrate the influence of perturbations on the frequency splitting of the system.To generate higher-order exceptional points in a simple and robust way,a mirror-induced asymmetric backscattering approach is used.In addition to the exceptional-point enhanced sensing capabilities of such systems,also a cavity-selective sensitivity is achieved for particle sensing.The results are motivated by an effective Hamiltonian description and verified by full numerical simulations of the dielectric structure.
