Nonlinear microwave spin wave interferometer

The characteristics of a nonlinear microwave spin wave interferometer were experimentally studied for the first time. The interferometer was implemented according to a bridge scheme with a nonlinear spin wave phase shifter based on an yttrium-iron garnet film. The maximum sensitivity of the nonlinear interferometer with respect to the input signal level was reached with a phase shifter operating on the forward volume spin waves. In the GHz frequency range, an increase in the microwave power up to a few mW led to a signal phase shift exceeding 180 °.