2008/12/31 by A. Kleine, A. Baumgartner, J. Trbovic +1 · 3 citations
Physics and Astronomy · #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Surface and Thin Film Phenomena #cond-mat.mes-hall #cond-mat.supr-con
paper · pdf · doi:10.1209/0295-5075/87/27011
published as Europhys. Lett. 87, 27011 (2009) · 5 pages, 4 figures, submitted to PRL
arxiv created 2009/05/12 · openalex publication_date 2009/07/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
We report experiments in nanometer-scaled superconductor/normal metal hybrid devices which show that in a small window of contact resistances, crossed Andreev reflection (CAR) can dominate the nonlocal transport for all energies below the superconducting gap. Besides crossed Andreev reflection, elastic cotunneling (EC) and nonlocal charge imbalance can be identified as competing subgap transport mechanisms in temperature-dependent four-terminal nonlocal measurements. We demonstrate a systematic change of the nonlocal resistance vs. bias characteristics with increasing contact resistances, which can be varied in the fabrication process. For samples with higher contact resistances, CAR is weakened relative to EC in the midgap regime, possibly due to dynamical Coulomb blockade. Gaining control of crossed Andreev reflection is an important step towards the realization of a solid-state entangler.