title: Signatures of Hyperfine, Spin-Orbit, and Decoherence Effects in a Pauli Spin Blockade.
abstract: We detect in real time interdot tunneling events in a weakly coupled two-electron double quantum dot in GaAs. At finite magnetic fields, we observe two characteristic tunneling times T_{d} and T_{b}, belonging to, respectively, a direct and a blocked (spin-flip-assisted) tunneling. The latter corresponds to the lifting of a Pauli spin blockade, and the tunneling times ratio η=T_{b}/T_{d} characterizes the blockade efficiency. We find pronounced changes in the behavior of η upon increasing the magnetic field, with η increasing, saturating, and increasing again. We explain this behavior as due to the crossover of the dominant blockade-lifting mechanism from the hyperfine to spin-orbit interactions and due to a change in the contribution of the charge decoherence.
authors.affiliation: Department of Applied Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Fujita
authors.affiliation: Center for Emergent Matter Science (CEMS), RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan.|Institute of Physics, Slovak Academy of Sciences, 845 11 Bratislava, Slovakia.
authors.forename: P
authors.initials: P
authors.lastname: Stano
authors.affiliation: Department of Applied Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.|Center for Emergent Matter Science (CEMS), RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan.
authors.forename: G
authors.initials: G
authors.lastname: Allison
authors.affiliation: Department of Applied Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Morimoto
authors.affiliation: Department of Applied Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Sato
authors.affiliation: Department of Applied Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Larsson
authors.affiliation: Center for Emergent Matter Science (CEMS), RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan.
authors.forename: J-H
authors.initials: JH
authors.lastname: Park
authors.affiliation: Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraße 150, Gebäude NB, D-44780 Bochum, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Ludwig
authors.affiliation: Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraße 150, Gebäude NB, D-44780 Bochum, Germany.
authors.forename: A D
authors.initials: AD
authors.lastname: Wieck
authors.affiliation: The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 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.|Center for Emergent Matter Science (CEMS), RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Tarucha