Coulomb interactions-induced perfect spin-filtering effect in a quadruple quantum-dot cell

Kagan, M. Yu.; Val'kov, V. V.; Aksenov, S. V. JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 440 15-18; 10.1016/j.jmmm.2016.12.106 OCT 15 2017

A quadruple quantum-dot (QQD) cell is proposed as a spin filter. The transport properties of the QQD cell were studied in linear response regime on the basis of the equations of motion for retarded Green's functions. The developed approach allowed us to take into account the influence of both intra- and interdot Coulomb interactions on charge carriers' spin polarization. It was shown that the presence of the insulating bands in the conductance due to the Coulomb correlations results in the emergence of spin-polarized windows (SPWs) in magnetic field leading to the high spin polarization. We demonstrated that the SPWs can be effectively manipulated by gate fields and considering the hopping between central dots in both isotropic and anisotropic regimes.