On the use of double entanglement in four-photon experiments

Kaoru Sanaka

Pierre-Louis de Assis, M. A. D. Carvalho, L. P. Berruezo +4 more

Control of spatial quantum correlations in bi-photons is one of the fundamental principles of Quantum Imaging. Up to now, experiments have been restricted to controlling the state of a single bi-photon, by using linear optical elements. In this work we demonstrate experimental control of quantum correlations in a four-photon state comprised of two pairs of photons. Our scheme is based on a high-efficiency parametric downconversion source coupled to a double slit by a variable linear optical setup, in order to obtain spatially encoded qubits. Both entangled and separable pairs have been obtained, by altering experimental parameters. We show how the correlations influence both the interference and diffraction on the double slit.

Todd S. Larchuk

Manpreet Kaur, Mandip Singh

Double-double-slit thought experiment provides profound insight on interference of quantum entangled particles. This paper presents a detailed experimental realisation of quantum double-double-slit thought experiment with momentum entangled photons and theoretical analysis of the experiment. Experiment is configured in such a way that photons are path entangled and each photon can reveal the which-slit path information of the other photon. As a consequence, single photon interference is suppressed. However, two-photon interference pattern appears if locations of detection of photons are correlated without revealing the which-slit path information. It is also shown experimentally and theoretically that two-photon quantum interference disappears when the which-slit path of a photon in the double-double-slit is detected.

hui peng

The standard interpretation of Young’s double slit experiment is that the light behaves as waves before and after passing through the diaphragm of the double slit. Recently, the photon chamber has been proposed and utilized to study the behavior of photons near the detecting screen. The experiments show that the light behaves as photons propagating along the straight-line trajectories that distribute as waves. Furthermore, the photon chamber placed near the double slit shows the non-interference pattern. blob:https://www.techrxiv.org/d6d50163-0598-4007-9243-ca11c2d05e95 In this article we show how the non-interference pattern evolves gradually to the interference pattern in the same cross double slit experiment: (1) the convex lens is placed at 50 mm from the diaphragm of the cross double slit, the non-interference pattern shows and has four primary maximum intensities (Figure (a)); (2) at 100 mm, the four primary maximum intensities disappeared (Figure (b)); (3) at 200 mm (Figure (c)); (4) at 600 mm, the interference pattern shown (Figure (d)), namely the non-interference pattern evolves to the interference pattern. The optics wave and electromagnetic wave theories cannot interpret this phenomenon and thus, is incomplete. This phenomenon provides information for further theoretical development. The cross double slit experiment is complex than the double slit experiments. We briefly discuss the complexity of the cross double slit experiment and show the comparison of both.

Yoon-Ho Kim