Quantum Optics

Contextuality and entanglement are valuable resources for quantum computing and quantum information. Bell inequalities are used to certify entanglement; thus, it is important to understand why and how they are violated. Quantum mechanics and behavioral sciences teach us that random variables measuring the same content (the answer to the same Yes or No question) may vary, if measured jointly with other random variables. Alice and Bob raw data confirm Einsteinian non-signaling, but setting dependent experimental protocols are used to create samples of coupled pairs of distant outcomes and to estimate correlations. Marginal expectations, estimated using these final samples, depend on distant settings. Therefore, a system of random variables measured in Bell tests is inconsistently connected and it should be analyzed using a Contextuality-by-Default approach, what is done for the first time in this paper. The violation of Bell inequalities and inconsistent connectedness may be explained...

We demonstrate efficient generation of collinearly propagating, highly nondegenerate photon pairs in a periodically-poled lithium niobate cw parametric downconverter with an inferred pair generation rate of 1.4*10^7/s/mW of pump power. Detection of an 800-nm signal photon triggers a thermoelectrically-cooled 20%-efficient InGaAs avalanche photodiode for the detection of the 1600-nm conjugate idler photon. Using single-mode fibers as spatial mode filters, we obtain a signal-conditioned idler-detection probability of about 3.1%.

In this paper we study quantum mechanical phase distribution of some nonlinear optical phenomena in a general setting of interacting Fock space. We have investigated the optical phenomena of propagation through a nonlinear medium as in optical fiber and the process of photon absorption from a thermal beam. The input and output phase distribution have been investigated analytically in these two cases.

Quantum logic gates require qubits that can interact strongly with each other and with external fields while minimizing unwanted coupling to the decohering environment. Neutral atoms trapped in a far-off resonance optical lattice satisfy these criteria. The adjustable parameters of the lattice (e.g., laser polarization, frequency, intensity) allow one to design interactions for which atoms interact strongly via dipole-dipole interactions

Quantum entanglement, a term coined by Erwin Schrodinger in 1935, is a mechanical phenomenon at the quantum level wherein the quantum states of two (or more) particles have to be described with reference to each other though these particles may be spatially separated. This phenomenon leads to paradox and has puzzled us for a long time. The behaviour of entangled particles is apparently inexplicable, incomprehensible and like magic at work. Locality has been a reliable and fruitful principle which has guided us to the triumphs of twentieth century physics. But the consequences of the local laws in quantum theory could seem "spooky" and nonlocal, with some theorists questioning locality itself. Could two subatomic particles on opposite sides of the universe be really instantaneously connected? Is any theory which predicts such a connection essentially flawed or incomplete? Are the results of experiments which demonstrate such a connection being misinterpreted? These question...

We report a quantum interference of nondiffracting beams by using photon pairs generated by spontaneous parametric down-conversion. The photon pairs transmitted by two double annular aperture produce fourth-order interference pattern along the transverse plane of detection as well as along the propagation distance. The latter presents a typical behaviour of the so-called Talbot effect . Introduction During the last few years, the properties of nondiffracting beams [1], also known as Bessel beams, have received attention by various authors. Recently, the superluminal behavior of these beams has been under investigation from a theoretical [2] and an experimental [3] point of view. An interesting self-imaging effect phenomenon, resulting from the superposition of two Bessel beams propagating in free space, has been predicted and experimentally demonstrated at a classical level [4]. On the other hand, the correlated photon pairs generated by spontaneous parametric down-conversion produc...

Magneto-optic surface plasmon resonance (MOSPR) based sensors are highly attractive as next generation biosensors. However, these sensors suffer from oxidation leading to degradation of performance, reproducibility of the sensor surface because of the difficulty of removing adsorbed materials, and degradation of sensor surface during surface cleaning, and these limit their applications. In this paper, I propose MOSPR-based biosensors with 0 to 15 nm thick inert polycarbonate laminate plastic as a protective layer and theoretically demonstrate the practicability of our approach in water-medium for three different probing samples: ethanol, propanol, and pentanol. I also investigate microstructure and magnetic properties. The chemical composition and ayered information of the sensor are investigated using X-ray reflectivity and X-ray diffraction analyses and these show distinct fcc-Au (111) phases, as dominated by the higher density of conduction electrons in Au as compared to Co. The magnetic characterization measured with the in-plane magnetic field to the sensor surface for both the as-deposited and annealed multilayers showed isotropic easy axis magnetization parallel to the multilayer interface at a saturating  magnetic field of < 100 Oe. The sensor showed a maximum sensitivity of 5.5 × 10 4 % / RIU for water-ethanol media and the highest detection level of 2.5×10-8 for water-pentanol media as the protective layer is increased from 0 to 15 nm.

As a step toward absolute calibration of optical tweezers, a first-principles theory of trapping forces with no adjustable parameters, corrected for spherical aberration, is experimentally tested. Employing two very different setups, we find generally very good agreement for the transverse trap stiffness as a function of microsphere radius for a broad range of radii, including the values employed in practice, and at different sample chamber depths. The domain of validity of the WKB (``geometrical optics'') approximation to the theory is verified. Theoretical predictions for the trapping threshold, peak position, depth variation, multiple equilibria, and ``jump'' effects are also confirmed.

Absorption  and  dispersion  properties  of  a  V-shaped  quantum-dot  molecule  are  investigated.  The  effect  of
decay-induced  interference  and  inter-dot  tunneling  on  phase  control  of  the  absorption  and  the  dispersion
is  then  discussed.  We  find  that  in  the  presence  of  decay-induced  interference  or  inter-dot  tunneling  the
group  velocity  of  a  light  pulse  is  completely  phase  dependant.  The  required  switching  times  for  switching
the  group  velocity  of  a  light  pulse  from  subluminal  to  superluminal  pulse  propagation  is  then  discussed.

Page 1. Quantum Communications: Present Status and Future Prospects Prem Kumar, Joseph B. Altepeter, and Matthew A. Hall ... 16 J. Chen, et al. “Demonstration of a Quantum Controlled-NOT Gate in the Telecom Band,” Phys. Rev. Lett. 100, 133603 (2008). 17 NI Nweke, et al. ...

A superluminal quantum-vortex model of the electron and the positron is produced from a superluminal double-helix model of the photon during electron-positron pair production. The two oppositely-charged (with Q = ±e sqrt (2/α) = 16.6e) open-helix spin-½ half-photons compose the double-helix photon. These half-photons separate and curl up their separated superluminal single-helical trajectories to form an electrically-charged superluminal closed-helix spin-½ quantum-vortex electron model and a corresponding positron model. The helical radius and the Dirac equation's zitterbewegung angular frequency of the quantum vortex electron and positron models equal the helical radius and zitterbewegung angular frequency of the two spin-½ half-photons, each of energy E = mc^2 , that composed the double-helix photon model of energy E = 2mc^2 from which the electron and positron models were produced. The photon and electron models are also compatible when a photon of energy E > 2mc^2 produces a relativistic electron-positron pair. Implications of the quantum vortex electron model for electron stability are discussed.

Movement/propagation through the “Dark Matter”:
Effects the surrounding by propagation through “Dark matter” particles creating “waves” in a manner similar to a Ship/boat moving in water creating waves

When two ships/boats (in our case two objects) move in parallel (in 4th dimension) to each other in the same direction, they experience a lateral pressure due to which the ships/boats tend to come closer to each other. This is explained by Bernoulli's theorem. This greater lateral pressure forces the ships/boats to come closer to each other and they may even collide
In our case the ships/boats are any aggregate of “Atoms” – any kind of an object
The “Sea” is the “Dark Matter”
Bernoulli's theorem is named after Daniel Bernoulli

With the advancement of wireless communication, optical wireless communication (OWC) has evolved into a communication method with a wide range of applications. However, different nonlinear effects in optical wireless communication will cause significant signal processing issues and degrade the system's performance. When paired with the visible light of machine learning methods, machine learning has a lot of potential for tackling nonlinear problems. Communication technology must be extremely valuable in terms of research. Traditional machine learning techniques like KGmeans, DBSCAN, and support vector machines (SVM) have been proven to perform well in pre-equalization, post-equalization, anti-system jitter, and phase correction in studies. The aforementioned methodologies are discussed and introduced, as well as their applications in the field of optical wireless communication signal processing, in the hopes of providing a reference for machine learning to handle numerous nonlinear problems in optical wireless communication. Because of its high nonlinear fitting capabilities, the deep neural network (DNN) can help the OWC system operate even better.

In this paper we raise questions about the reality of computational quantum parallelism. Such questions are important because while quantum theory is rigorously established, the hypothesis that it supports a more powerful model of computation remains speculative. More specifically, we suggest the possibility that the seeming computational parallelism offered by quantum superpositions is actually effected by gate-level parallelism in the reversible implementation of the quantum operator. In other words, when the total number of logic operations is analyzed, quantum computing may not be more powerful than classical. This fact has significant public policy implications with regard to the relative levels of effort that are appropriate for the development of quantumparallel algorithms and associated hardware (i.e., qubit-based) versus quantum-scale classical hardware.

In this paper we have studied the statistical and squeezing proprieties of light produced by superposition of a pair of single-mode squeezed chaotic light beams. Applying density operator of single-mode squeezed chaotic state; we obtain the anti-normal order characteristics function which enables us to find the Q function. With the resulting Q function, we calculate the photon statistics and the Quadrature squeezing for single-mode squeezed chaotic light. Moreover applying Q function of single-mode squeezed chaotic state the superposed light beams would be driven. With the resulting Q function we calculated the photon statics and the quadrature squeezing for superposed light beams. To get the maximum squeezing to be 95%, for nth = 0 and r = 1.5. 1 Introduction The most important quantum states of light are chaotic state, coherent state and squeezed state. Chaotic state is one of the classical features of light with super-Poissonian photon statics. And its best example is thermal light. The coherent state is a specific superposition of number states which does not possess number of photons as well as it is known by minimum uncertainty and poissonian photon statistics. Squeezed state satisfies non-classical feature of light, with sub-poissonian photon statistics [1]-[4]. The quantum distribution of radiation is the core idea in quantum optics. This used to describe the quantum properties of light. Some of them are the P function, the Wigner function and the Q functions. The P-function is c-number function with the anti-normal order density operator over π. And used to describe the superposition of two light beams with different states but having the same frequency. The Wigner function is the c-number function corresponding to the symmetric order density operator over π. The Q function is the most widely used one because, it is used to describe the superposition of two light beams with the same frequency but may be in the same or different states. This is described in terms of normally ordered density operator divided by π [5].

The squeezing, and statistical properties of a superposed light beam produced by a lambda type three-level lasers configuration have been studied. We have determined the quadrature variances mean as well as variance photon number for cavity modes with the aid of the solutions of c-number Langevin equations associated with the normal order. We have carried out our analysis a light in a squeezing state can be produced by the system under consideration under the condition that the cavity decay constant is larger than the linear gain coefficient and the squeezing occurs in the minus-quadrature. Furthermore, we also obtain with the aid of the Q-functions and the density operator the superposition beam, and superposed light beams are determined in quadrature variance and mean photon number. The result shows that the mean photon number and the quadrature variance of the superposed light beam are the sum of the mean photon number and the quadrature variance of the constituent light beams.

The magnetic dipole field geometry of subatomic elementary particles like the electron differs from the classical macroscopic field imprint of a bar magnet. It resembles more like an eight figure or else joint double quantum-dots instead of the classical, spherical more uniform field of a bar magnet. This actual subatomic quantum magnetic field of an electron at rest, is called Quantum Magnet or else a Magneton. It is today verified experimentally by quantum magnetic field imaging methods and sensors like SQUID scanning magnetic microscopy of ferromagnets and also seen in Bose-Einstein Condensates (BEC) quantum ferrofluids experiments. Normally, a macroscale bar magnet should behave like a relative giant Quantum Magnet with identical magnetic dipole field imprint since all of its individual magnetons collectively inside the material, dipole moments are uniformly aligned forming the total net field of the magnet. However due to Quantum Decoherence (QDE) phenomenon at the macroscale and macroscopic magnetic field imaging sensors limitations which cannot pickup these rapid quantum magnetization fluctuations, this field is masked and not visible at the macroscale. By using the relative inexpensive submicron resolution Ferrolens quantum magnetic optical superparamagnetic thin film sensor for field real time imaging and method we have researched in our previous publications, we can actually make this net magneton field visible on macroscale magnets. We call this net total field herein, Quantum Field of Magnet (QFM) differentiating it therefore from the field of the single subatomic magneton thus quantum magnet. Additionally, the unique potential of the Ferrolens device to display also the magnetic flux lines of this macroscopically projected giant Magneton gives us the opportunity for the first time to study the individual magnetic flux lines geometrical pattern that of a single subatomic magneton. We describe this particular magnetic flux of the magneton observed, quantum magnetic flux. Therefore an astonishing novel observation has been made that the Quantum Magnetic Field of the Magnet-Magneton (QFM) consists of a dipole vortex shaped magnetic flux geometrical pattern responsible for creating the classical macroscopic N-S field of magnetism as a tension field between the two polar quantum flux vortices North and South poles. A physical interpretation of this quantum decoherence mechanism observed is analyzed and presented and conclusions made showing physical evidence of the quantum origin irrotational and therefore conservative property of magnetism and also demonstrating that ultimately magnetism at the quantum level is an energy dipole vortex phenomenon.

The No-communication Theorem has been seen as the bar to communication by quantum state collapse. The essence of this theory is the procedure of taking the partial trace on an entangled, hence inseparable multi-particle system. This mathematical procedure applied unthinkingly, strikes out the off-diagonal elements from the ensemble density matrix and renders the reduced trace matrix representative of a mixed state. Decoherence theory is able to justify this mathematical procedure and we review it to show: the partial trace results for both unitary and non-unitary processes (hence measurement) on one, several or all particles of the ensemble; and that a unitary process keeps interference terms in the trace reduced matrix.

For a long time, one of my dreams was to describe the nature of uncertainty axiomatically, and it looks like I've finally done it in my co∼eventum mechanics! Now it remains for me to explain to everyone the co∼eventum mechanics in the most approachable way. This is what I'm trying to do in this work. The co∼eventum mechanics is another name for the co∼event theory, i.e., for the theory of experience and chance which I axiomatized in 2016 [1, 2]. In my opinion, this name best reflects the co∼event-based idea of the new dual theory of uncertainty, which combines the probability theory as a theory of chance, with its dual half, the believability theory as a theory of experience. In addition, I like this new name indicates a direct connection between the co∼event theory and quantum mechanics, which is intended for the physical explanation and description of the conict between quantum observers and quantum observations [4]. Since my theory of uncertainty satises the Kolmogorov axioms of probability theory, to explain this co∼eventum mechanics I will use a way analogous to the already tested one, which explains the theory of probability as a theory of chance describing the results of a random experiment. The simplest example of a random experiment in probability theory is the " tossing a coin ". Therefore, I decided to use this the simplest random experiment itself, as well as the two its analogies: the " "flipping a coin " and the " spinning a coin " to explain the co∼eventum mechanics, which describes the results of a combined experienced random experiment. I would like to resort to the usual for the probability theory " coin-based " analogy to explain (and first of all for myself) the logic of the co∼eventum mechanics as a logic of experience and chance. Of course, this analogy one may seem strange if not crazy. But I did not come up with a better way of tying the explanations of the logic of the co∼eventum mechanics to the coin-based explanations that are commonly used in probability theory to explain at least for myself the logic of the chance through a simple visual " coin-based " model that clarifies what occurs as a result of a combined experienced random experiment in which the experience of observer faces the chance of observation. I hope this analogy can be useful not only for me in understanding the co∼eventum mechanics.

By the 1950's it was generally agreed that "the photon's wave and quanta (particle) qualities are two observable aspects of a single phenomenon, and cannot be described by any mechanical model." (Joos, George. Theoretical Physics. London and Glasgow: Blackie and Son Ltd. (1951). In other words, it is somehow both a wave and a particle, but the most recent research in optics has shown that it can, in fact be "be described by [a quite simple] mechanical model"-- a particle that travels along a tight spiral path.

Although the postulate of " photon-having-zero-rest-mass " became over the years a sort of " dogma " , routinely repeated in thousands of physics textbooks and scientific articles, great physicists like two " fathers " of Quantum Mechanics: Erwin Schrödinger and Louis De Broglie, never believed that photons were really " massless " at rest, and many other remarkable physicists challenged this conviction as well. In recent years (2001-2005), the experiments through which Lene Westengarten Hau succeeded in slowing down, stopping, and making restart a laser light pulse by making it pass through optical molasses and ultra-cold sodium vapors of BEC (Bose-Einstein Condensates) can be interpreted as final and persuading evidence that photons –being both particles and e.m. waves-do possess a rest mas and they can be damped in " classical " and quantum ways as damped harmonic oscillators (classical) and superposing waves (QM). Therefore the speed of light is neither an universal constant (c), nor it is " invariant under Lorentz' transformations " , thereby destroying the 2 main pillars of Einstein's SR (Special Relativity). " There must be no barriers to freedom of inquiry. There is no place for dogma in science. The scientist is free, and must be free to ask any question, to doubt any assertion, to seek for any evidence, to correct any errors. " (J. Robert Oppenheimer)