The skyrmion generator is one of the indispensable components for the future functional skyrmion devices,but the process of generating skyrmion cannot avoid mixing with other magnetic textures,such as skyrmionium and ...The skyrmion generator is one of the indispensable components for the future functional skyrmion devices,but the process of generating skyrmion cannot avoid mixing with other magnetic textures,such as skyrmionium and nested skyrmion bags.These mixed magnetic textures will inevitably lead to the blockage of skyrmion transport and even the distortion of data information.Therefore,the design of an efficient skyrmion filter is of great significance for the development of skyrmion-based spintronic devices.In this work,a skyrmion filter scheme is proposed,and the high-efficiency filtering function is demonstrated by micromagnetic simulations.The results show that the filtering effect of the scheme depends on the structure geometry and the spin current density that drives the skyrmion.Based on this scheme,the polarity of the filtered skyrmion can be controlled by switching the magnetization state at the output end,and the“cloning”of the skyrmion can be realized by geometric optimization of the structure.We believe that in the near future,the skyrmion filter will become one of the important components of skyrmion-based spintronic devices in the future.展开更多
Non-magnetic semiconductor materials and their devices have attracted wide attention since they are usually prone to exhibit large positive magnetoresistance(MR)effect in a low static magnetic field environment at roo...Non-magnetic semiconductor materials and their devices have attracted wide attention since they are usually prone to exhibit large positive magnetoresistance(MR)effect in a low static magnetic field environment at room temperature.However,how to obtain a large room-temperature negative MR effect in them remains to be studied.In this paper,by designing an Au/n-Ge:Sb/Au device with metal electrodes located on identical side,we observe an obvious room-temperature negative MR effect in a specific 50 T pulsed high magnetic field direction environment,but not in a static low magnetic field environment.Through the analysis of the experimental measurement of the Hall effect results and bipolar transport theory,we propose that this unconventional negative MR effect is mainly related to the charge accumulation on the surface of the device under the modulation of the stronger Lorentz force provided by the pulsed high magnetic field.This theoretical analytical model is further confirmed by regulating the geometry size of the device.Our work sheds light on the development of novel magnetic sensing,magnetic logic and other devices based on non-magnetic semiconductors operating in pulsed high magnetic field environment.展开更多
We investigate asymmetric spin wave scattering behaviors caused by vortex chirality in a cross-shaped ferromagnetic system by using the micromagnetic simulations.In the system,four scattering behaviors are found:(i)as...We investigate asymmetric spin wave scattering behaviors caused by vortex chirality in a cross-shaped ferromagnetic system by using the micromagnetic simulations.In the system,four scattering behaviors are found:(i)asymmetric skew scattering,depending on the polarity of vortex core,(ii)back scattering(reflection),depending on the vortex core stiffness,(iii)side deflection scattering,depending on structural symmetry of the vortex circulation,and(iv)geometrical scattering,depending on waveguide structure.The first and second scattering behaviors are attributed to nonlinear topological magnon spin Hall effect related to magnon spin-transfer torque effect,which has value for magnonic exploration and application.展开更多
Fast in situ switching of magnetic vortex core in a ferromagnetic nanodisk assisted by a nanocavity,with diameter comparable to the dimension of a vortex core,is systematically investigated by changing the strength as...Fast in situ switching of magnetic vortex core in a ferromagnetic nanodisk assisted by a nanocavity,with diameter comparable to the dimension of a vortex core,is systematically investigated by changing the strength as well as the diameter of the effective circular region of the applied magnetic field.By applying a local magnetic field within a small area at the nanodisk center,fast switching time of about 35 ps is achieved with relatively low field strength(70 mT)which is beneficial for fast data reading and writing.The reason for this phenomenon is that the magnetic spins around the nanocavity is aligned along the cavity wall due to the shape anisotropy when the perpendicular field is applied,which deepens the dip around the vortex core,and thus facilitates the vortex core switching.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.12364020)the Scientific and Technological Development Plan of Jilin Province,China(Grant No.20240101295JC)+1 种基金the Science and Technology Research and Planning Project of Jilin Provincial Department of Education(Grant No.JJKH20230611KJ)the Applied Foundation Research Project(Talent Funding Project)of Yanbian University(Grant No.ydkj202241).
文摘The skyrmion generator is one of the indispensable components for the future functional skyrmion devices,but the process of generating skyrmion cannot avoid mixing with other magnetic textures,such as skyrmionium and nested skyrmion bags.These mixed magnetic textures will inevitably lead to the blockage of skyrmion transport and even the distortion of data information.Therefore,the design of an efficient skyrmion filter is of great significance for the development of skyrmion-based spintronic devices.In this work,a skyrmion filter scheme is proposed,and the high-efficiency filtering function is demonstrated by micromagnetic simulations.The results show that the filtering effect of the scheme depends on the structure geometry and the spin current density that drives the skyrmion.Based on this scheme,the polarity of the filtered skyrmion can be controlled by switching the magnetization state at the output end,and the“cloning”of the skyrmion can be realized by geometric optimization of the structure.We believe that in the near future,the skyrmion filter will become one of the important components of skyrmion-based spintronic devices in the future.
基金Project supported by the Special Funding for Talents of Three Gorges University(Grant No.8230202)the National Natural Science Foundation of China(Grant No.12274258)National Key R&D Program of China(Grant No.2016YFA0401003).
文摘Non-magnetic semiconductor materials and their devices have attracted wide attention since they are usually prone to exhibit large positive magnetoresistance(MR)effect in a low static magnetic field environment at room temperature.However,how to obtain a large room-temperature negative MR effect in them remains to be studied.In this paper,by designing an Au/n-Ge:Sb/Au device with metal electrodes located on identical side,we observe an obvious room-temperature negative MR effect in a specific 50 T pulsed high magnetic field direction environment,but not in a static low magnetic field environment.Through the analysis of the experimental measurement of the Hall effect results and bipolar transport theory,we propose that this unconventional negative MR effect is mainly related to the charge accumulation on the surface of the device under the modulation of the stronger Lorentz force provided by the pulsed high magnetic field.This theoretical analytical model is further confirmed by regulating the geometry size of the device.Our work sheds light on the development of novel magnetic sensing,magnetic logic and other devices based on non-magnetic semiconductors operating in pulsed high magnetic field environment.
基金Project supported by the Basic Science Research Program of the National Research Foundation of Korea(Grant No.2021R1F1A1050539)the Yanbian University Research Project(Grant No.482022104)the Yichang Natural Science Research Project(Grant No.A22-3-010)。
文摘We investigate asymmetric spin wave scattering behaviors caused by vortex chirality in a cross-shaped ferromagnetic system by using the micromagnetic simulations.In the system,four scattering behaviors are found:(i)asymmetric skew scattering,depending on the polarity of vortex core,(ii)back scattering(reflection),depending on the vortex core stiffness,(iii)side deflection scattering,depending on structural symmetry of the vortex circulation,and(iv)geometrical scattering,depending on waveguide structure.The first and second scattering behaviors are attributed to nonlinear topological magnon spin Hall effect related to magnon spin-transfer torque effect,which has value for magnonic exploration and application.
基金Supported by the Fund of Key Laboratory of Advanced Materials of Ministry of Education(Grant No.ADV21-20)。
文摘Fast in situ switching of magnetic vortex core in a ferromagnetic nanodisk assisted by a nanocavity,with diameter comparable to the dimension of a vortex core,is systematically investigated by changing the strength as well as the diameter of the effective circular region of the applied magnetic field.By applying a local magnetic field within a small area at the nanodisk center,fast switching time of about 35 ps is achieved with relatively low field strength(70 mT)which is beneficial for fast data reading and writing.The reason for this phenomenon is that the magnetic spins around the nanocavity is aligned along the cavity wall due to the shape anisotropy when the perpendicular field is applied,which deepens the dip around the vortex core,and thus facilitates the vortex core switching.
