Study Of Twisted Magnons

Spin,the intrisic physical quantity of electron,is one of the most important unit carrier in information handling and storage.However,spin-flipping and-precession related methods can no longer fulfill the demand for multi-functional devices needed in next-generation information industry,due to their non-locality and extremely high energy consumption.Spin-waves,being the low-energy excitation in magnetic ordered system,outstand themselves for ultra-GHz eigen-fraquency,micro-/nano-wavelength and non-Joule transmission,which will become ideal candidates for storing,computing and transfering information via spins.The quanta of spin-waves,Magnon,is a Bosonic elemental excitation in magnetic ordered system and carries one unit of spin angular moment.Howerver,the tiny angular moment of magnon,as well as the damping effects in magnets,prevent it from being effectively and accurately steered in information convert between electric-and magnetic-subsystems.In our paper,we propose to add a new twist to the planar exchange spin-waves as an orbital angular moment(OAM)to remove the barrier in the road of tranditional spin-wave spintronics.OAM can be tuned to any large enough value to produce topologically non-trivial spin-wave named TWSITED-MAGNON.On the other hand,OAM is bound to the topological charge of twisted-magnon,meaning it will not be dissipated by the Gilbert damping of the magnetic system due to that the topologcial chage is an intrisic physics of the twisted-magnon.These qualified properties of the twisted-magnon overcome the difficulties of tiny angular moment carried by spin-waves and exponential decay of their amplitude in transmission,which is of remarkable theoretical value and in hope of great application prospect.In 3-dimensional ferromagnetic wave guide,the orbital Hall effect,gyromagnetic effect and transmisson properties of the twisted-magnon can be steered via applied electric field.Furthermore,we can transfer information effectively through variety of interference patterns shaped by several twisted-magnons' superimposition.Twisted-magnons also adapted themselves in 2-dimensional ferromagnetic nano-disks which possess ??(2)symmetry.Their characteristics of spatial structures and topological properties in dynamical evolution are extractable via the spin pumping effect and the inverse spin Hall effect by electrical methods.Moreover,we also exhibit their transmission behavior between distinct ferromagnetic nano-disks.All these foundings will provide reliable theoretical corner-stone for novel,topological spin-wave-based and highly robust and damping-resisted magnonic devices.