Refraction of spin waves by bifocal surface ferromagnetic lens in external magnetic field

Behavior of spin-wave propagation in ferromagnetic medium with non-uniform distribution of magnetic parameters is studied. In particular, the influence of external magnetic field, spin-wave frequency and exchange parameter on behavior of surface spin-wave propagating through inhomogeneity made in form of lens (lens is biaxial ferromagnet placed into uniaxial ferromagnetic medium) is studied. - Highlights: → Spin-wave surface lens proposed. → Phenomenon of birefringence of spin-wave beam arises. → Focal distances can be changed in a wide range by only changing the magnetic field.