Rectifying full-counting statistics in a spin Seebeck engine

We investigate the rectification effect of a spin Seebeck engine in which the quantum dot (QD) is coupled to both the electronic reservoir and magnetic insulator. The scaled cumulant generating function (SCGF) of the system is expressed in the framework of nonequilibrium Green’s function. We present the rectification and negative differential effect of spin current and its higher order cumulants. The heat engine performances, such as the maximum output power and efficiency are also shown to exhibit rectification and negative differential effect. The strongly fluctuated interfacial electron density of states induced by QD is responsible for these intriguing properties. It can broaden our views of the nonequilibrium thermodynamics by studying the nontrivial phenomena occurred in the two terminal hybrid system involving both electronic and bosonic reservoir.