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
The influence of Dzyaloshinskii-Moriya interaction(DMI)on the vortex reversal driven by an out-of-plane spin-polarized current in an off-centered nanocontact structure is investigated.The simulation results show that ...The influence of Dzyaloshinskii-Moriya interaction(DMI)on the vortex reversal driven by an out-of-plane spin-polarized current in an off-centered nanocontact structure is investigated.The simulation results show that DMI plays a vital role in vortex core reversal,including reversal current density,reversal velocity and reversal time.Under the influence of DMI,magnetic vortices still reverse polarity through the nucleation and annihilation of vortex and anti-vortex,with some peculiar characteristics.These results open up new possibilities for the application of magnetic vortex-based spin-transfer encryption nano-storage.展开更多
Recent discoveries in the synthesis and applications of magnetic vortex nanorings/nanodiscs in theranostic applications are reviewed. First, the principles of nanomagnetism and magnetic vortex are introduced. Second, ...Recent discoveries in the synthesis and applications of magnetic vortex nanorings/nanodiscs in theranostic applications are reviewed. First, the principles of nanomagnetism and magnetic vortex are introduced. Second, methods for producing magnetic vortex nanorings/nanodiscs are presented. Finally, theranostic applications of magnetic vortex nanorings/nanodiscs are addressed.展开更多
This research work emphasizes the capability of delivering optically shaped targets through the interaction of nanosecond laser pulses with high-density gas-jet profiles,and explores proton acceleration in the near-cr...This research work emphasizes the capability of delivering optically shaped targets through the interaction of nanosecond laser pulses with high-density gas-jet profiles,and explores proton acceleration in the near-critical density regime via magnetic vortex acceleration(MVA).Multiple blast waves(BWs)are generated by laser pulses that compress the gas-jet into near-critical steep gradient slabs of a few micrometres thickness.Geometrical alternatives for delivering the laser pulses into the gas target are explored to efficiently control the characteristics of the density profile.The shock front collisions of the generated BWs are computationally studied by 3D magnetohydrodynamic simulations.The efficiency of the proposed target shaping method for MVA is demonstrated for TW-class lasers by a particle-in-cell simulation.展开更多
Switching the orientation of a vortex core by spin-polarised pulse current introduces a promising concept for the reliable addressing of a single nanodisc element inside dense arrays. In this paper, micromagnetic simu...Switching the orientation of a vortex core by spin-polarised pulse current introduces a promising concept for the reliable addressing of a single nanodisc element inside dense arrays. In this paper, micromagnetic simulations are employed to study the vortex core switching behaviour excited by a short in-plane Gaussian current pulse. We find that both the switching mechanism and the switching time are not sensitive to changes in the phenomenological parameters of spin-torque nonadiabaticity and Gilbert damping. The switching time, however, strongly depends on the current strength. In addition, we have theoretically predicted the parameter range of current pulses to achieve a single switching event.展开更多
We perform micromagnetic simulations on the switching of magnetic vortex core by using spin-polarized currents through a three-nanocontact geometry. Our simulation results show that the current combination with an app...We perform micromagnetic simulations on the switching of magnetic vortex core by using spin-polarized currents through a three-nanocontact geometry. Our simulation results show that the current combination with an appropriate current flow direction destroys the symmetry of the total effective energy of the system so that the vortex core can be easier to excite,resulting in less critical current density and a faster switching process. Besides its fundamental significance, our findings provide an additional route to incorporating magnetic vortex phenomena into data storage devices.展开更多
The longitudinal wave term within Faraday’s law of electromagnetic induction (Faraday’s law) underwent recovery to ensure its suitability for theoretical derivation of the equation governing longitudinal electromagn...The longitudinal wave term within Faraday’s law of electromagnetic induction (Faraday’s law) underwent recovery to ensure its suitability for theoretical derivation of the equation governing longitudinal electromagnetic (LEM) waves. The revised Maxwell’s equations include the crucial parameters being the attenuation time constants of magnetic vortex potential and electric vortex potential generated by external electromagnetic field within the propagation medium. Specific expressions for them are obtained through theoretical analysis. Subsequently, a model for propagating magnetic P-wave generated by the superposition of a left-handed photo and a right-handed photon in a vacuum is formulated based on reevaluated total current law and revised Faraday’s law, covering wave equations, energy equation, as well as propagation mode involving mutual induction and conversion between scalar magnetic field and vortex electric field. Furthermore, through theoretical derivations centered around magnetic P-wave, evidence was presented regarding its ability to absorb huge free energy through the entangled interaction between zero-point vacuum energy field and the torsion field produced by the vortex electric field.展开更多
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Project supported by the National Natural Science Foundation of China(Grant Nos.11774045 and 22078124)the Program for the Development of Science and Technology of Jilin Province,China(Grant No.20210101410JC).
文摘The influence of Dzyaloshinskii-Moriya interaction(DMI)on the vortex reversal driven by an out-of-plane spin-polarized current in an off-centered nanocontact structure is investigated.The simulation results show that DMI plays a vital role in vortex core reversal,including reversal current density,reversal velocity and reversal time.Under the influence of DMI,magnetic vortices still reverse polarity through the nucleation and annihilation of vortex and anti-vortex,with some peculiar characteristics.These results open up new possibilities for the application of magnetic vortex-based spin-transfer encryption nano-storage.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.21376192 and 81571809)the Research Fund for the Doctoral Program of Higher Education of China(Grant No.20126101110017)MOE Ac RF Tier 2-MOE2011-T2-1-043 and A-Star SERC 1321202068
文摘Recent discoveries in the synthesis and applications of magnetic vortex nanorings/nanodiscs in theranostic applications are reviewed. First, the principles of nanomagnetism and magnetic vortex are introduced. Second, methods for producing magnetic vortex nanorings/nanodiscs are presented. Finally, theranostic applications of magnetic vortex nanorings/nanodiscs are addressed.
基金supported by the National Key Research and Development Program of China(2016YFA0302300)the Beijing Natural Science Foundation(Z190008)+9 种基金the National Natural Science Foundation of China(11974052 and 11474024)the Beamline 1W1A of the Beijing Synchrotron Radiation Facilitythe National Natural Science Foundation of China(11604011)Beijing Institute of Technology Research Fund Program for Young Scholarsthe National Natural Science Foundation of China(11672264 and 11621062)support by the German Research Foundation DFG SFB TRR173 Spin+X,project KL1811/18the Graduate School of Excellence Materials Science in Mainz(GSC266)Peking University was supported by the National Key R&D Program of China(2016YFA0300804)the National Natural Science Foundation of China(11974023 and 51672007)the Key R&D Program of Guangdong Province(2018B030327001 and 2018B010109009).
基金The authors acknowledge support of this work by the project‘ELI-LASERLAB Europe Synergy,HiPER&IPERIONCH.gr’(MIS 5002735),which is implemented under the action‘Reinforcement of the Research and Innovation Infrastructure’,funded by the Operational programme‘Competitiveness,Entrepreneurship and Innovation’(NSRF 2014-2020)and co-financed by Greece and the European Union(European Regional Development Fund)supported by computational time granted by the Greek Research and Technology Network(GRNET)in the National HPC facility-ARIS-under project ID pr011027-LaMPIOS+1 种基金This work has been carried out within the framework of the EUROfusion Consortium,funded by the European Union via the Euratom Research and Training Programme(grant agreement No.101052200-EUROfusion)the Hellenic National Program of Controlled Thermonuclear Fusion.
文摘This research work emphasizes the capability of delivering optically shaped targets through the interaction of nanosecond laser pulses with high-density gas-jet profiles,and explores proton acceleration in the near-critical density regime via magnetic vortex acceleration(MVA).Multiple blast waves(BWs)are generated by laser pulses that compress the gas-jet into near-critical steep gradient slabs of a few micrometres thickness.Geometrical alternatives for delivering the laser pulses into the gas target are explored to efficiently control the characteristics of the density profile.The shock front collisions of the generated BWs are computationally studied by 3D magnetohydrodynamic simulations.The efficiency of the proposed target shaping method for MVA is demonstrated for TW-class lasers by a particle-in-cell simulation.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 50871075 and 10974142)the Natural Science Foundation of Shanghai,China (Grant No. 08ZR1420500)
文摘Switching the orientation of a vortex core by spin-polarised pulse current introduces a promising concept for the reliable addressing of a single nanodisc element inside dense arrays. In this paper, micromagnetic simulations are employed to study the vortex core switching behaviour excited by a short in-plane Gaussian current pulse. We find that both the switching mechanism and the switching time are not sensitive to changes in the phenomenological parameters of spin-torque nonadiabaticity and Gilbert damping. The switching time, however, strongly depends on the current strength. In addition, we have theoretically predicted the parameter range of current pulses to achieve a single switching event.
基金supported by the China Postdoctoral Science Foundation(Grant No.2013M541286)the Science and Technology Planning Project of Jilin Province,China(Grant Nos.20140520109JH and 20150414003GH)the “Twelfth Five year” Scientific and Technological Research Project of Department of Education of Jilin Province,China
文摘We perform micromagnetic simulations on the switching of magnetic vortex core by using spin-polarized currents through a three-nanocontact geometry. Our simulation results show that the current combination with an appropriate current flow direction destroys the symmetry of the total effective energy of the system so that the vortex core can be easier to excite,resulting in less critical current density and a faster switching process. Besides its fundamental significance, our findings provide an additional route to incorporating magnetic vortex phenomena into data storage devices.
文摘The longitudinal wave term within Faraday’s law of electromagnetic induction (Faraday’s law) underwent recovery to ensure its suitability for theoretical derivation of the equation governing longitudinal electromagnetic (LEM) waves. The revised Maxwell’s equations include the crucial parameters being the attenuation time constants of magnetic vortex potential and electric vortex potential generated by external electromagnetic field within the propagation medium. Specific expressions for them are obtained through theoretical analysis. Subsequently, a model for propagating magnetic P-wave generated by the superposition of a left-handed photo and a right-handed photon in a vacuum is formulated based on reevaluated total current law and revised Faraday’s law, covering wave equations, energy equation, as well as propagation mode involving mutual induction and conversion between scalar magnetic field and vortex electric field. Furthermore, through theoretical derivations centered around magnetic P-wave, evidence was presented regarding its ability to absorb huge free energy through the entangled interaction between zero-point vacuum energy field and the torsion field produced by the vortex electric field.
