title: Josephson current in strongly correlated double quantum dots.
abstract: We study the Josephson current through a serial double quantum dot and the associated 0-π transitions which result from the subtle interplay between the superconductivity, the Kondo physics, and the interdot superexchange interaction. The competition between them is examined by tuning the relative strength Δ/T(K) of the superconducting gap and the Kondo temperature, for different strengths of the superexchange coupling determined by the interdot tunneling t relative to the level broadening Γ. We find strong renormalization of t, a significant role of the superexchange coupling J, and a rich phase diagram of the 0 and π-junction regimes. In particular, when both the superconductivity and the exchange interaction compete with the Kondo physics (Δ∼J∼T(K)), there appears an island of π' phase at large values of the superconducting phase difference.
authors.affiliation: J. Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia.
authors.forename: Rok
authors.initials: R
authors.lastname: Zitko
authors.forename: Minchul
authors.initials: M
authors.lastname: Lee
authors.forename: Rosa
authors.initials: R
authors.lastname: López
authors.forename: Ramón
authors.initials: R
authors.lastname: Aguado
authors.forename: Mahn-Soo
authors.initials: MS
authors.lastname: Choi