Induced nonlinear phase shift of forward volume spin waves in magnetic films and one-dimensional magnonic crystals

A differential phase shift of a low-power spin wave (SW) induced by a high-power pumping wave co-propagating at different frequencies in perpendicularly magnetized magnetic films has been studied. We find that this effect for forward volume SWs propagating in yttrium iron garnet (YIG) films is stronger than that for surface SWs propagating in tangentially magnetized films. The results show that the induced nonlinear phase shift up to 180{\deg} takes place for pumping wave power of a few milliwatts. The phenomenon paves the way for fast and energy-efficient control of one-dimensional magnon transport.