Spin selective pseudogap Kondo effect in a double quantum dot interferometer with Rashba interaction

A system composed of two quantum dots, i.e. a strongly interacting Kondo dot and a noninteracting one, placed in the arms of the Aharonov-Bohm ring, is investigated theoretically. The ring is coupled to normal leads. This configuration is mapped on the system of a correlated impurity embedded in a host with energy and flux dependent density of states. Additionally, the presence of the Rashba field allows a spin selective opening of the pseudogap in the density of states of the host, when the level of the noninteracting dot is tuned to the Fermi energy. This selectively diminishes electron correlations in the Kondo dot and creates resultant spin polarization at the Fermi level. It is shown that this polarization arises in the absence of any exchange field. Interestingly, this Rashba-correlation-induced spin polarization reaches its maximum for the position of the Kondo dot level corresponding to the Kondo temperature of the Anderson impurity in the host with constant density of states.