Spin Wave Nonreciprocity due to Asymmetry of Propagation Length

Abstract

  Nonreciprocity of spin waves, which means the difference in amplitude depending on the direction of propagation, provides functionality to spin wave-based devices. One of the known origins of spin wave nonreciprocity is the asymmetry of the excitation efficiency due to the asymmetry of the out-of-plane microwave magnetic field generated by an antenna. We investigate the magnetic field angle dependence of spin wave nonreciprocity. We find that this nonreciprocity is due to the asymmetry of the propagation length in addition to the asymmetry of the excitation efficiency.