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Optical and Quantum Electronics

Detection of preexisting quantum entanglements between dipole–photon discrete observables

Elio B. Porcelli, Omar R. Alves, Victo S. Filho

Published Aug 18, 2023• 2 citations
Publisher

Abstract

Abstract We performed measurements of laser beam power polarized in different angles as 0 $$^\circ $$ ∘ , 45 $$^\circ $$ ∘ and 90 $$^\circ $$ ∘ passing close to a symmetric shielded capacitor with parallel plates and through a polaroid filter configured with angles as 0 $$^\circ $$ ∘ , 45 $$^\circ $$ ∘ and 90 $$^\circ $$ ∘ . An unusual light power variation was detected during the charging and discharging of the high voltage capacitor even considering the suppression of known electromagnetic interaction between laser beam and capacitor. The light power variation curves also indicated a typical pattern of charge and discharge of capacitors. The combination of the angles of the laser beam polarization and polaroid filter surprisingly indicated the measurement of correlations between the polarizations of photons and electric dipoles of the capacitor dielectric. These novel results can only be explained supposing the preexisting condition of quantum entanglements between discrete observables of electric dipoles and photons.

DOI
10.1007/s11082-023-05216-7

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Abstract We performed measurements of laser beam power polarized in different angles as 0 ∘^\circ ∘ ∘ , 45 ∘^\circ ∘ ∘ and 90 ∘^\circ ∘ ∘ passing close to a symmetric shielded capacitor with parallel plates and through a polaroid filter configured with angles as 0 ∘^\circ ∘ ∘ , 45 ∘^\circ ∘ ∘ and 90 ∘^\circ ∘ ∘ . An unusual light power variation was detected during the charging and discharging of the high voltage capacitor even considering the suppression of known electromagnetic interaction between laser beam and capacitor. The light power variation curves also indicated a typical pattern of charge and discharge of capacitors. The combination of the angles of the laser beam polarization and polaroid filter surprisingly indicated the measurement of correlations between the polarizations of photons and electric dipoles of the capacitor dielectric. These novel results can only be explained supposing the preexisting condition of quantum entanglements between discrete observables of electric dipoles and photons.
We propose experiments on quantum entanglement for investigating the Einstein Podolsky Rosen (EPR) problem with the polarization directions of photons. These experiments are performed to investigate whether the defined polarization directions in an entangled state are teleported between entangled photons. EPR-type sequential experiments are performed using a twin-photon beam and two pairs of linear polarization analyzers under the cross-Nicol condition (i.e., orthogonal to each other). If the third filter whose polarization angle is 45 degrees is set between the first cross-Nicol filters, the beam intensity is changed from 0 to 12.5 %, and at the second cross-Nicol filters, the beam intensity is changed from 0 to 25 %. In this experiment, we predict that the "continuity of quantum entanglement" under a pure Hamiltonian evolution is detected.
We report the efficient creation and detection of hybrid entanglement between one photon's polarization and another photon's complex transverse polarization pattern including various polarization singularities. The polarization measurement of the first photon triggers a polarization-sensitive imaging of its partner photon, the vector photon, using a single-photon-sensitive camera. Thereby, the vector photon's complex polarization pattern is reconstructed tomographically dependent on the type of polarization measurement performed on its partner. To evaluate the quality of the observed patterns, we introduce a fidelity-like measure which compares the reconstructed polarization with the theoretically expected one at every transverse spatial position. We find that the measured polarization patterns and the theory overlap by more than 90%. Moreover, we visualize the varying strengths of polarization entanglement for different transverse regions and demonstrate an interesting phenomenon: Each vector photon can be both entangled and not entangled in polarization with its partner photon. We give an intuitive, information-theoretical explanation for our results. Our results pave the way to study quantum properties of the rich field of such complex light modes with the potential to improve various applications in quantum informational tasks.
In this work single capacitor paradox (a variation of the remarkable two capacitor paradox) is considered in a new, quantum discrete form. Simply speaking we consider well-known usual, photoelectric effect experimental device, i.e. photo electric cell, where cathode and anode are equivalently charged but non-connected. It, obviously, represents a capacitor that initially, i.e. before action of the photons with individual energy equivalent to work function, holds corresponding energy of the electrical fields between cathode and anode. Further, we direct quantum discretely photons, one by one, toward cathode where according to photo-electrical effect electrons discretely, one by one, will be emitted and directed toward anode. It causes discrete discharge of the cell, i.e. capacitor and discrete decrease of the electrical field. Finally, total discharge of the cell, i.e. capacitor, and total disappearance of the electrical field and its energy will occur. Given, seemingly paradoxical, capacitor total energy loss can be simply explained without any dissipative effects (Joule heating or electromagnetic waves emission can be neglected as high order small corrections) by work done by the electrical field by movement of the electrons from cathode to anode. (Remarkable two capacitors paradox can be, obviously, formulated and explained in the completely analogous way.)
This paper proposes a scheme to guide cold polar molecules by using a single charged wire half embanked in an insulating substrate and a homogeneous bias electric field, which is generated by a plate capacitor composed of two infinite parallel metal plates. The spatial distributions of the electrostatic field produced by the combination of the charged wire and the plate capacitor and the corresponding Stark potentials (including dipole forces) for metastable CO molecules are calculated, the relationships between the electric field and the parameters of our charged-wire layout are analysed. It also studies the influences of the insulator on the electric field distribution and the discharge effect. This study shows that the proposed scheme can be used to guide cold polar molecules in the weak-field – seeking states, and to form various molecule-optical elements, such as molecular funnel, molecular beam-splitters and molecule interferometer, even to construct a variety of integrated molecule-optical elements and their molecule chips.
Entanglement is a key resource for fundamental tests of physics and emerging quantum technologies. In quantum optics, two perspectives on entanglement coexist. In the continuous-variable framework, entanglement is understood as holding between optical modes. In contrast, discrete-variable quantum optics focuses on quantum correlations in degrees of freedom such as polarization that label fixed numbers of photons. In this paper, we show that entanglement can transcend this separation. Spontaneous parametric down-conversion inherently generates correlations in optical phase space, photon number, and labelling degrees of freedom simultaneously. In polarization, this structure is traditionally described by macroscopic Bell states. Existing witnesses, however, fail to detect the genuine hybrid entanglement of these states, which goes beyond the continuous-discrete-variable categorization. Here, we lay the groundwork for a general framework unifying continuous- and discrete-variable notions of entanglement. In particular, we derive an operational witness providing a sufficient criterion for genuine hybrid number-polarization entanglement and outline its experimental implementation. Finally, we discuss exemplary states which, together with our results on macroscopic Bell states, motivate a broader classification of genuine hybrid quantum correlations.
It is commonly believed that photon polarization entanglement can only be obtained via pair creation within the same source or via postselective measurements on photons that overlapped within their coherence time inside a linear optics setup. In contrast to this, we show here that polarization entanglement can also be produced by distant single photon sources in free space and without the photons ever having to meet, if the detection of a photon does not reveal its origin—the which way information. In the case of two sources, the entanglement arises under the condition of two emissions in certain spatial directions and leaves the dipoles in a maximally entangled state.