2011/03/31 by T. Eberle, Tobias Eberle, Vitus Händchen +4 · 6 citations
Computer Science · Physics and Astronomy · #EPR paradox #Physics #Quantum #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum entanglement #Quantum key distribution #Quantum mechanics #Quantum optics and atomic interactions #quant-ph
paper · pdf · doi:10.1103/physreva.83.052329
published as Phys. Rev. A 83, 052329 (2011) · 4 pages, 4 figures
arxiv created 2011/05/30 · openalex publication_date 2011/05/31 · arxiv updated 2015/05/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Einstein-Podolsky-Rosen (EPR) entanglement is a criterion that is more demanding than just certifying entanglement. We theoretically and experimentally analyze the low-resource generation of bipartite continuous-variable entanglement, as realized by mixing a squeezed mode with a vacuum mode at a balanced beam splitter, i.e., the generation of so-called vacuum-class entanglement. We find that in order to observe EPR entanglement the total optical loss must be smaller than 33.3 %. However, arbitrarily strong EPR entanglement is generally possible with this scheme. We realize continuous-wave squeezed light at 1550 nm with up to 9.9 dB of nonclassical noise reduction, which is the highest value at a telecom wavelength so far. Using two phase-controlled balanced homodyne detectors we observe an EPR covariance product of 0.502\ifmmode±\else\textpm\fi0.006<1, where 1 is the critical value. We discuss the feasibility of strong Gaussian entanglement and its application for quantum key distribution in a short-distance fiber network.