Super-Poissonian shot noise of squeezed-magnon mediated spin transport

الأصل · EN

The magnetization of a ferromagnet (F) driven out of equilibrium injects pure spin current into an adjacent conductor (N). Such F|N bilayers have become basic building blocks in a wide variety of spin based devices. We evaluate the shot noise of the spin current traversing the F|N interface when F is subjected to a coherent microwave drive. We find that the noise spectrum is frequency independent up to the drive frequency, and increases linearly with frequency thereafter. The low frequency noise indicates super-Poissonian spin transfer, which results from quasi-particles with effective spin ℏ* = ℏ (1 + δ). For typical ferromagnetic thin films, δ 1 is related to the dipolar interaction-mediated squeezing of F eigenmodes.