Steady and dynamic magnetic phase transitions in the open interacting quantum dots arrays

Abstract We apply the mean-field Hubbard model, non-equilibrium Green’s function (NEGF) theory and the hierarchical equations of motion (HEOM) method to investigate some magnetic phase transitions in the 1D interacting quantum dots arrays (QDA) sandwiched by non-interaction leads. We find that with a weak device-leads coupling, there exists a ferrimagnetic state in the uniform odd-numbered or the staggered-hopping QDA systems. With increasing the coupling strength, temperature or the bias potential, the extra spin-polarized electrons flow out of the QDA, which results in a magnetism-to-nonmagnetism phase transition. With the spin-resolved HEOM method, we also investigate the transient spin dissipation process in these phase transitions. When applying an abrupt large bias potential or a strong device-leads coupling, the spin polarized electrons decay with oscillations from the QDA into electrodes. We believe our results may be helpful in the future quantum computation devices.