Experimental non-classicality of an indivisible system

ORAL

Abstract

In Quantum Mechanics (QM) not all properties can be simultaneously well defined. An important question is whether a joint probability distribution can describe the outcomes of all possible measurements, allowing a quantum system to be mimicked by classical means. Klyachko et al. [PRL 101, 020403 (2008)] derived an inequality which allowed us to answer this question experimentally. The inequality involves only five measurements and QM predicts its violation for single spin-1 particles. This is the simplest system where such a contradiction is possible. It is also indivisible and as such cannot contain entanglement. In our experiment with single photons distributed among three modes (isomorphic to stationary spin-1 particles) we obtained a value of -3.893(9), which lies more than 90 standard deviations below the ``classical'' bound of -3.

*Supported by ERC (Advanced Grant QIT4QAD), the Austrian Science Fund (Grant F4007), the EU (Contract No. MRTN-CT-2006-035369 (EMALI)).

–

Authors

  • Radek Lapkiewicz

    • University of Vienna, Faculty of Physics, Vienna; Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences, Vienna
    • University of Vienna, Faculty of Physics, IQOQI Vienna, Austrian Academy of Sciences, Austria

  • Peizhe Li

    • University of Vienna, Faculty of Physics, Vienna; Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences, Vienna
    • University of Vienna, Faculty of Physics, IQOQI Vienna, Austrian Academy of Sciences, Austria

  • Christoph Schaeff

    • University of Vienna, Faculty of Physics, Vienna; Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences, Vienna
    • University of Vienna
    • University of Vienna, Faculty of Physics, IQOQI Vienna, Austrian Academy of Sciences, Austria

  • Nathan Langford

    • University of Vienna, Faculty of Physics, Vienna; Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences, Vienna

  • Sven Ramelow

    • University of Vienna, Faculty of Physics, Vienna; Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences, Vienna
    • University of Vienna, Faculty of Physics, IQOQI Vienna, Austrian Academy of Sciences, Austria

  • Marcin Wiesniak

    • University of Vienna, Faculty of Physics, Vienna; Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences, Vienna
    • University of Vienna, Faculty of Physics, IQOQI Vienna, Austrian Academy of Sciences, Austria

  • Anton Zeilinger

    • Austrian Academy of Sciences
    • University of Vienna, Faculty of Physics, Vienna; Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences, Vienna
    • University of Vienna
    • University of Vienna, Faculty of Physics, IQOQI Vienna, Austrian Academy of Sciences, Austria