Thermal bistability of magnon in yttrium iron garnet microspheres.

In this work, the thermal bistability of magnons in yttrium iron garnet microspheres was experimentally characterized. Using high quality factor optical whispering gallery modes in the microsphere, the temperature change caused by the microwave pump is precisely measured by probing the optical resonance wavelength shift. It is found that temperature change also induces the magnonic frequency shift and the frequency shift depends on the crystal axis direction of the material. With some appropriate alignment of the magnetic field and the microsphere, the magnonic frequency shift induced by the thermal bistability from the microwave can be suppressed. Our results show its potential use in future experiments on magnon-based transducers. [ABSTRACT FROM AUTHOR]