Altermagnetism,a recently identified class of collinear magnetism,combines key features of antiferromagnets and ferromagnets.Despite having zero net magnetization,altermagnetic materials exhibit anomalous transport ef...Altermagnetism,a recently identified class of collinear magnetism,combines key features of antiferromagnets and ferromagnets.Despite having zero net magnetization,altermagnetic materials exhibit anomalous transport effects,including the anomalous Hall,Nernst,and thermal Hall effects,as well as magneto-optical Kerr and Faraday effects.These phenomena,previously thought unique to ferromagnets,are dictated by symmetry,as confirmed by density functional theory(DFT)calculations.However,an effective model-based approach to verify these symmetry constraints remains unavailable.In this Letter,we construct a k·ρ model for d-wave altermagnets CuX_(2)(X=F,Cl)using spin space group representations and apply it to calculate the anomalous Hall effect.The symmetry-imposed transport properties predicted by the model are in agreement with the DFT results,providing a foundation for further investigation into symmetry-restricted transport phenomena in altermagnetic materials.展开更多
Random optical systems have been widely investigated due to their abundant physical effects,including numerous degrees of freedom and equilibrium states.Whereas the boundary perturbation can disturb the dynamical beha...Random optical systems have been widely investigated due to their abundant physical effects,including numerous degrees of freedom and equilibrium states.Whereas the boundary perturbation can disturb the dynamical behavior of the equilibrium states and lead to a series of unexplored evolution,here we unveil the equilibrium transition induced by boundary perturbation in random fiber lasers through introducing a laser-feedback process.In this typical random optical system,the predominant role of random scattering can be manipulated by a laser-feedback process that serves as boundary perturbation,causing the transition of the equilibrium state and output properties of the laser.On this basis,the photon lifetime can also be reduced,presenting huge potential in highly sensitive non-contact sensing with a detectable minimum feedback power of 12.08 f W and a detection distance of130 km.Our work provides a new perspective in deepening the understanding of intrinsic mechanisms in random systems and broadens the underlying applications,including modal manipulation and high sensitivity measurement.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.12274117)the Natural Science Foundation of Henan(Grant No.242300421214)+4 种基金the Program for Innovative Research Team(in Science and Technology)in the University of Henan Province(Grant No.24IRTSTHN025)the Open Fund of Guangdong Provincial Key Laboratory of Nanophotonic Manipulation(No.202502)Guangdong S&T Program(No.2023B1212010008)the High-Performance Computing Center of Henan Normal Universitysupported by the U.S.DOE,Office of Science(Grant No.DE-FG02-05ER46237)。
文摘Altermagnetism,a recently identified class of collinear magnetism,combines key features of antiferromagnets and ferromagnets.Despite having zero net magnetization,altermagnetic materials exhibit anomalous transport effects,including the anomalous Hall,Nernst,and thermal Hall effects,as well as magneto-optical Kerr and Faraday effects.These phenomena,previously thought unique to ferromagnets,are dictated by symmetry,as confirmed by density functional theory(DFT)calculations.However,an effective model-based approach to verify these symmetry constraints remains unavailable.In this Letter,we construct a k·ρ model for d-wave altermagnets CuX_(2)(X=F,Cl)using spin space group representations and apply it to calculate the anomalous Hall effect.The symmetry-imposed transport properties predicted by the model are in agreement with the DFT results,providing a foundation for further investigation into symmetry-restricted transport phenomena in altermagnetic materials.
基金National Natural Science Foundation of China(62275001,62205001,62405001,62105001)Natural Science Foundation of Anhui Province(2408085QF206)。
文摘Random optical systems have been widely investigated due to their abundant physical effects,including numerous degrees of freedom and equilibrium states.Whereas the boundary perturbation can disturb the dynamical behavior of the equilibrium states and lead to a series of unexplored evolution,here we unveil the equilibrium transition induced by boundary perturbation in random fiber lasers through introducing a laser-feedback process.In this typical random optical system,the predominant role of random scattering can be manipulated by a laser-feedback process that serves as boundary perturbation,causing the transition of the equilibrium state and output properties of the laser.On this basis,the photon lifetime can also be reduced,presenting huge potential in highly sensitive non-contact sensing with a detectable minimum feedback power of 12.08 f W and a detection distance of130 km.Our work provides a new perspective in deepening the understanding of intrinsic mechanisms in random systems and broadens the underlying applications,including modal manipulation and high sensitivity measurement.
