Experimental violation of three families of Bell's inequalities

Abstract

Bell's inequalities are important to our understanding of quantum foundations and critical to several quantum technologies. A recent work [E. Wolfe and S. F. Yelin, Phys. Rev. A 86, 012123 (2012)] derived three parametrized families of two-particle, two-setting Bell inequalities. These inequalities are important as they theoretically explore a larger volume of allowed quantum correlations over local hidden-variable models than previous results [A. Cabello, Phys. Rev. A 72, 012113 (2005)] by exploiting marginal, or single particle measurements. In this work we subject those predictions to experimental test using nonmaximally entangled photon pairs to optimize the expected violation. We find excellent agreement with the upper bounds predicted by quantum mechanics with violations of the limits imposed by local hidden-variable models as large as almost 30σ for the optimal parameters and a significant violation over a wide range of parameters.

Nonexistence of Quantum Nonlocality

“…In a vast and ever growing literature, of which [1][2][3][4][5][6][7][8][9][10][11] is but a selection of relatively recent examples, the claim is made that quantum mechanics is nonlocal because its predictions, confirmed by experiment, violate various Bell inequalities. Entire books [12,13] have been written in support of this thesis, and one is often given the impression that nonlocality is not only part of current quantum mechanics, but will be a part of any future theory that gives the same predictions for certain experimental situations.…”

Pulsed Sagnac polarization-entangled photon source with a PPKTP crystal at telecom wavelength

“…However, in all the previous experiments [13][14][15][16][17][18][19][20][21][22][23], the entangled photons were generated at around 800 nm wavelength. In this work, we expand such pulsed PPKTP-Sagnac scheme into a group-velocity matched (GVM) regime and demonstrate a GVM-PPKTP-Sagnac scheme at the telecom wavelength.…”

“…In 2012, Predojević et al, investigated the phase property of this system [17]. Now this PPKTP-Sagnac scheme has become a common tool for the generation of polarization-entangled state and has applied in many experiments [18][19][20][21][22][23].…”

CW-pumped telecom band polarization entangled photon pair generation in a Sagnac interferometer

“…Then, a pulsed polarization entangled source at 780 nm based on this configuration was developed by Kuzucu and Wong in 2008 [21]. Now, polarization entangled sources based on QPM crystals in a Sagnac configuration have become a basic tool for many experiments [22][23][24][25][26][27][28]. In the early experiments, the wavelengths of the photons generated are in visible range, therefore these photons are not suitable for long distance quantum communications in fiber.…”