2005/01/31 by S. Russo, Saverio Russo, M. Kroug +3 · 9 citations
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #cond-mat.mes-hall #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevlett.95.027002
4 pages, 4 figures. Accepted for publication in PRL
arxiv created 2005/05/28 · openalex publication_date 2005/07/08 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We investigate transport through hybrid structures consisting of two normal metal leads connected via tunnel barriers to one common superconducting electrode. We find clear evidence for the occurrence of nonlocal Andreev reflection and elastic cotunneling through a superconductor when the separation of the tunnel barrier is comparable to the superconducting coherence length. The probability of the two processes is energy dependent, with elastic cotunneling dominating at low energy and nonlocal Andreev reflection at higher energies. The energy scale of the crossover is found to be the Thouless energy of the superconductor, which indicates the phase coherence of the processes. Our results are relevant for the realization of recently proposed entangler devices.