title: Cooper pair splitting in parallel quantum dot Josephson junctions.
abstract: Devices to generate on-demand non-local spin entangled electron pairs have potential application as solid-state analogues of the entangled photon sources used in quantum optics. Recently, Andreev entanglers that use two quantum dots as filters to adiabatically split and separate the quasi-particles of Cooper pairs have shown efficient splitting through measurements of the transport charge but the spin entanglement has not been directly confirmed. Here we report measurements on parallel quantum dot Josephson junction devices allowing a Josephson current to flow due to the adiabatic splitting and recombination of the Cooper pair between the dots. The evidence for this non-local transport is confirmed through study of the non-dissipative supercurrent while tuning independently the dots with local electrical gates. As the Josephson current arises only from processes that maintain the coherence, we can confirm that a current flows from the spatially separated entangled pair.
authors.affiliation: 1] Advanced Device Laboratory, RIKEN, Wako 351-0198, Japan [2] Center for Emergent Matter Science (CEMS), RIKEN, Wako 351-0198, Japan.
authors.forename: R S
authors.initials: RS
authors.lastname: Deacon
authors.affiliation: The Institute of Scientific and Industrial Research, Osaka University 8-1 Mihogaoka, Ibaraki 567-0047, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Oiwa
authors.affiliation: Department of Applied Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Sailer
authors.affiliation: Department of Applied Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Baba
authors.affiliation: The Institute of Scientific and Industrial Research, Osaka University 8-1 Mihogaoka, Ibaraki 567-0047, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kanai
authors.affiliation: 1] Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan [2] INQIE, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Shibata
authors.affiliation: 1] Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan [2] INQIE, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan [3] JST CREST, 4-1-8 Hon-cho, Kawaguchi-shi, Saitama 332-0012, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Hirakawa
authors.affiliation: 1] Center for Emergent Matter Science (CEMS), RIKEN, Wako 351-0198, Japan [2] Department of Applied Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan [3] INQIE, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan [4] QPEC, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Tarucha