Nonreciprocity and Unidirectional Invisibility in Cavity Magnonics

非互易双稳态在耦合非线性谐振腔磁学中的实现

Nonreciprocal Bistability in Coupled Nonlinear Cavity Magnonics

该研究通过引入非线性元件，实现基于凯尔磁子的高可调非互易双稳态系统，展示了在不同耦合条件下增强磁子非互易性的方法。

Spin-wave nonreciprocity based on interband magnonic transitions

We theoretically demonstrate linear spin-wave nonreciprocity in a Ni80Fe20 nanostripe waveguide, based on interband magnonic transitions induced by a time-reversal and spatialinversion symmetry breaking magnetic field. An analytical coupled-mode theory of spin waves, developed to describe the transitions which are accompanied by simultaneous frequency and wavevector shifts of the coupled spin waves, is well corroborated by numerical simulations. Our findings could pave the way for the realization of spin-wave isolation and the dynamic control of spin-wave propagation in nanoscale magnonic inte…

Spin wave nonreciprocity and magnonic band structure in thin permalloy film induced by dynamical coupling with an array of Ni stripes

An efficient way for the control of spin wave propagation in a magnetic medium is the use of periodic patterns known as magnonic crystals (MCs). However, the fabrication of MCs especially bi-components, with periodicity on nanoscale, is a challenging task due to the requirement for sharp interfaces. An alternative method to circumvent this problem is to use homogeneous ferromagnetic film with modified periodically surrounding. The structure is also suitable for exploiting nonreciprocal properties of the surface spin waves. In this work, we demonstrate that the magnonic band structure forms in …

受限纳米磁体中的环形矩及其对磁振子学的影响

Toroidal Moments in Confined Nanomagnets and their Impact on Magnonics

该研究建立了受限纳米磁体中环形矩的计算判据，厘清其不同定义的关联，拓展了环形矩的物理意义，为磁振子系统非互易性的识别与估算提供了更通用的方法。

Laser-induced magnonic band gap formation and control in YIG/GaAs heterostructure

We demonstrate the laser-induced control over spin-wave (SW) transport in the magnonic crystal (MC) waveguide formed from the semiconductor slab placed on the ferrite film. We considered bilayer MC with periodical grooves performed on the top of the n-type gallium arsenide slab side that oriented to the yttrium iron garnet film. To observe the appearance of magnonic gap induced by laser radiation, the fabricated structure was studied by the use of microwave spectroscopy and Brillouin light-scattering. We perform detailed numerical studies of this structure. We showed that the optical control o…

Nonreciprocal Multi-mode and Indirect Couplings in Cavity Magnonics

We investigate the magnon-photon couplings by employing a small magnet within an irregular resonant cavity, which leads to a desirable nonreciprocity with a big isolation ratio. Moreover, the higher-order couplings between the spin wave modes with the polarized photon modes also exhibit the nonreciprocity. These couplings between polarized photon and spin waves could be regarded as an indirect multi-modes coupling between the ferromagnetic resonance (FMR) mode and spin wave mode magnons mediated by the cavity mode photons. We also derive a coupling matrix to predict the characteristics of this…