Shifting the quantum-classical boundary: theory and experiment for statistically classical optical fields
Optica, 2 (7):
611--615 (July 2015)DOI: 10.1364/OPTICA.2.000611
Abstract
The growing recognition that entanglement is not exclusively a quantum property, and does not even originate with Schr&\#xF6;dinger&\#x2019;s famous remark about it \\Proc. Cambridge Philos. Soc.31, 555 (1935)PCPSA40008-198110.1017/S0305004100013554\\, prompts the examination of its role in marking the quantum-classical boundary. We have done this by subjecting correlations of classical optical fields to new Bell-analysis experiments and report here values of the Bell parameter greater than B\$=\$2.54. This is many standard deviations outside the limit B\$=\$2 established by the Clauser&\#x2013;Horne&\#x2013;Shimony&\#x2013;Holt Bell inequality \\Phys. Rev. Lett.23, 880 (1969)10.1103/PhysRevLett.23.880PRLTAO0031-9007\\, in agreement with our theoretical classical prediction, and not far from the Tsirelson limit B\$=\$2.828&\#x2026;. These results cast a new light on the standard quantum-classical boundary description, and suggest a reinterpretation of it.