title: Fast spin information transfer between distant quantum dots using individual electrons.
abstract: Transporting ensembles of electrons over long distances without losing their spin polarization is an important benchmark for spintronic devices. It usually requires injecting and probing spin-polarized electrons in conduction channels using ferromagnetic contacts or optical excitation. In parallel with this development, important efforts have been dedicated to achieving control of nanocircuits at the single-electron level. The detection and coherent manipulation of the spin of a single electron trapped in a quantum dot are now well established. Combined with the recently demonstrated control of the displacement of individual electrons between two distant quantum dots, these achievements allow the possibility of realizing spintronic protocols at the single-electron level. Here, we demonstrate that spin information carried by one or two electrons can be transferred between two quantum dots separated by a distance of 4 μm with a classical fidelity of 65%. We show that at present it is limited by spin flips occurring during the transfer procedure before and after electron displacement. Being able to encode and control information in the spin degree of freedom of a single electron while it is being transferred over distances of a few micrometres on nanosecond timescales will pave the way towards 'quantum spintronics' devices, which could be used to implement large-scale spin-based quantum information processing.
authors.affiliation: Université Grenoble Alpes, Institut NEEL, F-38042 Grenoble, France.|CNRS, Institut NEEL, F-38042 Grenoble, France.
authors.forename: B
authors.initials: B
authors.lastname: Bertrand
authors.affiliation: Université Grenoble Alpes, Institut NEEL, F-38042 Grenoble, France.|CNRS, Institut NEEL, F-38042 Grenoble, France.
authors.forename: S
authors.initials: S
authors.lastname: Hermelin
authors.affiliation: Université Grenoble Alpes, Institut NEEL, F-38042 Grenoble, France.|CNRS, Institut NEEL, F-38042 Grenoble, France.|Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Takada
authors.affiliation: Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan.|PRESTO-JST, Kawaguchi-shi, Saitama 331-0012, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Yamamoto
authors.affiliation: Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan.|RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako-Shi, Saitama 31-0198, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Tarucha
authors.affiliation: Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany.
authors.forename: A
authors.identifier: 0000-0002-2871-7789
authors.initials: A
authors.lastname: Ludwig
authors.affiliation: Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany.
authors.forename: A D
authors.initials: AD
authors.lastname: Wieck
authors.affiliation: Université Grenoble Alpes, Institut NEEL, F-38042 Grenoble, France.|CNRS, Institut NEEL, F-38042 Grenoble, France.
authors.forename: C
authors.initials: C
authors.lastname: Bäuerle
authors.affiliation: Université Grenoble Alpes, Institut NEEL, F-38042 Grenoble, France.|CNRS, Institut NEEL, F-38042 Grenoble, France.
authors.forename: T
authors.initials: T
authors.lastname: Meunier