Magnon Pumping by a Time-Dependent Transverse Magnetic Field in   Ferromagnetic Insulators
  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. 
Kouki Nakata and Gen Tatara
cond-mat.mes-hall cond-mat.str-el