Current noise geometrically generated by a driven magnet

Abstract

We consider a non-equilibrium cross-response phenomenon, whereby a driven magnetization gives rise to electric shot noise (but no d.c. current). This effect is realized on a nano-scale, with a small metallic ferromagnet which is tunnel-coupled to two normal metal leads. The driving gives rise to a precessing magnetization. The geometrically generated noise is related to a non-equilibrium distribution in the ferromagnet. Our protocol provides a new channel for detecting and characterizing ferromagnetic resonance.