Magnetic polarization currents in parallel-coupled double-quantum-dot devices

We theoretically study the properties of the magnetic polarization currents (MPC) in parallel-coupled double-quantum-dot devices by means of the two-impurity Anderson Hamiltonian and Green functions. It is shown that at zero temperature, the Kondo effect of the system becomes weaker with the increase of the coupling strength. At low temperature, by varying some conditions such as temperature and bias voltage, the direction and magnitude of MPC can be changed, which implies that the magnetic states of the device can be mode up-, non- or down-polarized.