Dicke-like effect in spin-polarized transport through coupled quantum dots

Spin-dependent electronic transport through a quantum dot side-coupled to two quantum dots and attached to ferromagnetic leads with collinear (parallel and antiparallel) magnetizations is analyzed theoretically. The intra-dot Coulomb correlations are taken into account, whereas the inter-dot ones are neglected. Transport characteristics, i.e. conductance and tunnel magnetoresistance associated with the magnetization rotation from parallel to antiparallel configurations, are calculated by the non-equilibrium Green's function technique. The Green's functions are derived by the equation of motion method in the Hartree-Fock approximation. The conductance spectra are shown to reveal features similar to the Dicke resonance in atomic physics