Magnon Pumping by a Time-Dependent Transverse Magnetic Field in Ferromagnetic Insulators

Abstract

The magnon pumping effect in ferromagnetic insulators under an external time-dependent transverse magnetic field is theoretically studied. Generation of a magnon current is discussed by calculating the magnon source term in the spin continuity equation. This term represents the non-conservation of magnons arising from an applied transverse magnetic field. The magnon source term has a resonance structure as a function of the angular frequency of the transverse field, and this fact is useful to enhance the pumping effect.

5 pages, 3 figures, added references, accepted for publication in J.Phys.Soc.Jpn