Reconfigurable Spin-Wave Nonreciprocity Induced by Dipolar Interaction in a Coupled Ferromagnetic Bilayer

Abstract

In the growing field of $m\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}g\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}o\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}c\phantom{\rule{0}{0ex}}s$, spin waves (magnons) are manipulated as information carriers, particularly for data processing. Thus controlling the propagation of spin waves is of paramount interest here. This investigation considers a ferromagnetic bilayer with dipolar coupling as a potential nonreciprocal magnonic device, in which frequency dispersion is reciprocal for parallel yet nonreciprocal for antiparallel orientation of layer magnetizations. This is progress in the technological implementation of magnonic devices with asymmetric transmission properties, since reconfigurability can be easily achieved just by switching, without any rotation of the applied magnetic field.