Magnetic Field and Temperature-Dependent Brillouin Light Scattering Spectra of Magnons in Yttrium Iron Garnet

Knowledgeof the magnon responses to an external magnetic fieldand temperature is significant for spintronics applications. Herein,exploiting Brillouin light scattering (BLS) spectroscopy, we investigatethe magnetic field and temperature dependence of the magnon frequency,line width, and intensity in yttrium iron garnet (YIG). The appliedmagnetic field here can effectively change the magnon frequency whilemaintaining the lifetime of the magnon. Specifically, we determinethe temperature dependence of magnon frequency and the linear relationshipbetween magneto-optic effects-related terms (|A ((+))|(2)/|A ((-))|(2)) and temperature below room temperature (RT), which can serveas a temperature sensor. Our results open an avenue to sense the temperatureand the external magnetic field, including the effective magneticfield induced by the magnetic proximity effect. Furthermore, our resultsprovide a route toward designing the operating frequency and lossof the devices, facilitating future research in spin-related applications,including magnon-based logic, memory, sensing, and thermospin devices.