Photon

Background: Biological shielding of nuclear reactors has always been a great concern and decreasing the complexity and expense of these installations is of great interest. In this study, we used datolite and galena (DaGa) minerals for production of a high performance heavy concrete. Materials and Methods: Datolite and galena minerals which can be found in many parts of Iran were used in the concrete mix design. To measure the gamma radiation attenuation of the DaGa concrete samples, they were exposed to both narrow and wide beams of gamma rays emitted from a cobalt-60 radiotherapy unit. An Am-Be neutron source was used for assessing the shielding properties of the samples against neutrons. To test the compression strengths, both types of concrete mixes (DaGa and ordinary concrete) were investigated. Results: The concrete samples had a density of 4420-4650 kg/m 3 compared to that of ordinary concrete (2300-2500 kg/m 3 ) or barite highdensity concrete (up to 3500 kg/m3). The measured ...

Photon correlation measurements on single InAs/ GaAs quantum rings embedded in a photonic crystal lattice demonstrate single-photon emission with g ͑2͒ ͑0͒ values of 0.4 and photon antibunching between the exciton and biexciton emissions. The measured photon antibunching times of the excitons are longer than that of the biexcitons, resulting in the time asymmetry of the exciton-biexciton photon cross-correlation. Phonon sidebands due to the piezoelectric coupling of excitons to acoustic phonons broaden the emission lines and shift them to lower energies at low excitation intensity.

According to Yangton and Yington Theory, only spin particles such as photon and electron can have wave particle duality. Appling particle waves in study of Single Slit Diffraction and Double Slit Interference, a new type of mechanisms: attractive interference and repulsive interference are proposed instead of constructive interference and destructive interference, which gives a better explanation to particle depletion in destructive interference. In case of single particle experiment, subject to the traveling time, direction and distance of each particle, attractive interference and repulsive interference can still happen but at much less frequency. Furthermore, which-way experiment and the Complementarity Principle are proven incorrect and both particle and wave properties on photon and electron can coexist at the same time.

The method which was used in development of Fundamental Electro-Magneto-Mechanics theory is: "Within existing confirmed and affirmed physics, identify the essential, fundamental phenomena, equations, and concepts, base their definitions exclusively on facts, and make only and exclusively the commonsense, simple, and unambiguous conclusions, immediately derived from facts, immediately relying on facts.". In one sentence: "Try to reach optimum of consistency and completeness, with minimal abstraction.". Briefly and concretely, the starting base consists of elementary energy (a photon), space and time, and their most basic relations and properties. The results obtained are unprecedented, in each and every respect.

There is always another way to say the same thing that doesn't look at all like the way it was said before." Richard Feynman. In this essay, a novel approach to cosmology is presented that mathematically models the Universe as an iterated function system (IFS) analogous to the famous Mandelbrot Set IFS (M): z=z 2 +c, where z and c are complex numbers. In theoretical physics, wavefunctions are functions of a complex space that are commonly used to model the dynamics of particles and waves. In the IFS framework presented herein, complex dynamical systems are generated via the iteration process, where the act of iteration corresponds to 1) a change in the state of the system and 2) a change to the wavefunction itself. In this manner, M can be considered a wavefunction generator. In this framework, all observables, including gravity and time, are thought to be generated by the iteration process. Feynman understood that there are many ways of looking at the Universe that are equivalent in nature but different psychologically. Understanding cosmology in terms of fractals and iterated function systems requires a paradigm shift in the way we approach cosmology. This is an evidence based dissertation and does not contradict the standard model; rather, it attempts to reconstruct it using the principles of the fractal paradigm as outlined in this essay. It is the contention of the author that in order to understand the true nature of light, the universe and everything, we must first understand the important role that fractal cosmology plays in the study of our complex dynamical universe.

The photoelectric effect is commonly used as the introductory topic for the study of quantum physics. However, there are various indicators that some instructional materials and approaches to the topic contain deficiencies and even factual errors. A major aspect of instruction is the historical and scientific background for the photoelectric effect. In this paper, I outline the key elements of the history of the discovery of the photoelectric effect, of Einstein's light-quantum theory, and of the ultimate acceptance of the theory that are necessary for developing sound instructional materials.

A model of the electron is proposed in which it is composed of a known and detectable particle. This model clearly defines what is mass, what is energy and why E = mc 2 . It shows that the special relativity corrections of mass, length and time with velocity are automatically a function of the structure of an electron as it moves. It also proposes the origin of electric charge and uses that origin to derive the equation for the Bohr magnetron. It shows that the electron's spin of ½ħ is simply angular momentum, further explaining why the electron has only two states of spin. This model gives an expression for the radius of an electron, at the same time pointing out why it has been detected as a point particle, yet still has angular momentum of ½ħ. It explains why the mass of an electron increases with velocity while its spin and charge remain the same and its magnetic moment decreases, as well as why its charge spirals when it travels through space. This model gives a physical reason for the existence of the de Broglie wavelength and derives the expression for it. As well as matching the known properties of an electron it also makes predictions of previously unknown properties, pointing out that they may have been detected but not recognized as such.

Acceleration Doppler Effect is introduced to explain the Redshift phenomenon in Inertia Transformation process. Hubble's Law and Cosmological Redshift are interpreted by Wu's Spacetime Accelerating Shrinkage Theory. In addition, Wu's Laws of Spacetime of Wu's Pair and Photon with respect to the age of universe and the gravitational field are derived and summarized.

James Clerk Maxwell unknowingly discovered a correct relativistic, quantum theory for the light quantum, forty-three years before Einstein postulated the photon's existence. In this theory, the usual Maxwell field is the quantum wave function for a single photon. When the non-operator Maxwell field of a single photon is second quantized, the standard Dirac theory of quantum optics is obtained. Recently, quantum-state tomography has been applied to experimentally determine photon wave functions.

There is a widespread view in contemporary physics that the electric field of an electromagnetic wave is in the phase with the magnetic field. This statement is incorrect. The article discloses in detail that the above statement leads to violating the law of energy conservation.
The right statement is that electric and magnetic fields in the photon are shifted mutually by 90 degrees. In this case the electric field converts to the magnetic field and vice versa. The energy of the photon over time remains constant.

In this paper, we develop the model of the four-level double Raman pairs by exploiting the required optimal conditions for this system that are feasible with real experimental realization. We investigate qualitatively the entanglement, statistical properties, and geometric phase for the pair of Stokes and anti-Stokes photons in the presence of the time-dependent coupling effect. We show that these quantifiers are very sensitive to the change of the Rabi frequency and time, exhibiting substantial phenomena that are depending on the kind of coupling between the atom and photons. Finally, we explore the relationship between the quantum quantifiers in terms of the physical parameters with and without timedependent coupling effect.

Abstract: In material world matter provides substance to all real entities. Hence, it is logical to conceive development-hierarchy of various matter-particles, starting from unstructured matter, rather than bifurcating superior matter-particles into inferior ones on the basis of noticed properties. Diverse properties of various matter-particles are derived from immediate inferior matter-particles and depend on their physical structures. Very brief account of development of various matter-particles, from unstructured matter, as conceived in alternative concept presented in book ‘MATTER (Re-examined)’, is presented in this article.

We derive a simple expression for the photon helicity and polarisation-flip probabilities in arbitrary background fields, in the low energy regime. Taking the background to model a focused laser beam, we study the impact of pulse shape and collision geometry on the probabilities and on ellipticity signals of vacuum birefringence. We find that models which do not account for pulse duration can overestimate all signals in near head-on collisions by up to an order of magnitude. Taking pulse duration into account, the flip probability becomes relatively insensitive to both angular incidence and the fine details of the pulse structure.

Postplacental IUD is a post-partum contraceptive device that can be inserted directly in the first 10 minutes after the placenta is born. The low interest in post-placental IUD use is strongly influenced by husband's support. This study aims to determine the relationship between husband's support and the use of the postplacental IUD as a post-delivery family planning program. This type of research is analytic observational with a cross sectional approach. The sample of this study was 62 mothers giving birth at the Pratama Clinic Kusuma Medisca Wates taken by simple random sampling technique. The research instrument used a husband's support questionnaire. Data analysis was performed by Chi Square test. Maternal mothers who used the postplacenta IUD were more mothers who received husband's support (40.3%) compared to mothers who did not receive husband's support. Statistical test results obtained p-value 0.000, prevalence rate 5.26 with a confidence interval range ...

The alleged existence of quantum with momentum in electromagnetic radiation is disputed, this is within the supposed balance of both Einstein's mass-energy equivalent with Planck's radiation energy, we realize this is untrue, except at one energy state represented by a single frequency, from the whole frequency spectrum; this formula is also analyzed and compared with the balance between kinetic energy and the Planck's radiation energy, the energy as well as the momentum for each is derived and showed to relate to an equivalent radiation energy and momentum equivalent to momentums given by mV and mc, which was coined for particle's mass; a momentum derived from the multiplication of Radiation Magnetic Force (F_mR) and change in time (Δt), designated as Magnetic Momentum (ρ_M), is related to the Electron Momentum (ρ_E) and both are in odd with the Compton Momentum (ρ_C), which showed great discrepancies with momentum of both the ρ_M€ and ρ_E, when plotted graphically; the paper established the condition for radiation momentum to remove electron from atom, which is only fulfilled by the Magnetic Momentum (ρ_M), rather than Compton Momentum (ρ_C); thus a conclusion is reached that, the use of the formula by Compton was not justified, it was misleading, and doesn't uphold scientific merit, while the Radiation Magnetic Force (F_mR) embedded in the electromagnetic radiation, is the force gives the proper and logical momentum that ejected photoelectrons and carried different mechanism in Compton Effect and others; this attempt aimed at restoring the common sense to the physical world.

The decay of photon by the influence of magnetic field is considered. It is shown here that if the photon energy is grater than 1 MeV then photon can decay electron positron pair, but if it remains below 1 MeV then photon decays into neutrino antineutrino pair. The decay rates for both of the processes are calculated. All possible Feynman diagrams are taken into account to construct the matrix element for either of the processes. In the second process all three type of neutrinos are considered. The significance of these processes are discussed briefly.

Fungi LBKURCC43 merupakan fungi endofit yang diisolasi dari umbi tanaman dahlia berbunga ungu (Dahlia variabilis) di Padang Panjang, Sumatera Barat. Identifikasi secara morfologi isolat tersebut telah dilakukan dan hanya mengidentifikasi pada tingkat genus. Identifikasi secara molekuler dengan menggunakan DNA adalah identifikasi spesies yang lebih tepat digunakan. Sebelum dilakukan analisis filogenetik secara molekuler berdasarkan sekuens DNA ribosomal pada daerah ITS-1 dan ITS-2, dilakukan ekstraksi DNA dan amplikasi PCR ITS rDNA yang baik untuk sekuensing. DNA kromosomal diisolasi menggunakan kit Wizard Genomic Purification ex Promega Co (Madison, USA) dari sel miselia berumur tiga hari. Hasil penelitian menunjukkan bahwa DNA berhasil diisolasi dari miselia yang berumur tiga hari sebelum terbentuk spora dan jumlah yang cukup tinggi untuk PCR. DNA kromosomal fungi LBKURCC43 memiliki BM (berat molekul) 10.294 pb. ITS rDNA berhasil diamplifikasi dengan PCR menggunakan pasangan primer...

Absorbed dose and energy distribution of scattered photons that contaminate high-energy photon beams have been calculated for 6-MV and 21-MV bremsstrahlung sources using the Monte Carlo method. The percentage of the absorbed dose at the central axis is less than 3%. The results show that the main sources of scattered photons are the primary collimator for 6-MV and the flattening filter for 21-MV bremsstrahlung sources respectively. The absorbed dose from the phantom scattered photons has been calculated by a semi-empirical method. These calculations show that the dominating contribution to the absorbed dose outside the primary beam is due to these phantom scattered photons. In the surface region of the phantom, however, electrons from the air and collimators may give rise to a high absorbed dose.

At the University of Sussex we are building a coplanar-waveguide (CPW) Penning trap. This is a novel planar Penning trap, which results form the projection of the well-known cylindrical trap onto the surface of a chip [1]. The trap allows for the compensation of electrical anharmonicities up to the sixth order and permits the observation of a single trapped electron, a primary goal not yet achieved with planar Penning trap technology. The electron can be coupled to a distant superconducting coplanar-waveguide resonator, such as those used in circuit-QED with artificial two level systems. The cyclotron motion interacts coherently with the microwave resonator, implementing a system of two coupled quantum harmonic oscillators and with applications in quantum metrology and quantum computation. In the poster, we report on recent experimental progress in the construction of a cryogenic CPW- Penning trap.

Deterministic solid-state quantum light sources are key building blocks in photonic quantum technologies. While several proof-of-principle experiments of quantum communication using such sources have been realized, all of them required bulky setups. Here, we evaluate for the first time the performance of a compact and stand-alone fiber-coupled single-photon source emitting in the telecom O-band (1321nm) for its application in quantum key distribution (QKD). For this purpose, we developed a compact 19” rack module including a deterministically fiber-coupled quantum dot single-photon source integrated into a Stirling cryocooler, a pulsed diode laser for driving the quantum dot, and a fiber-based spectral filter. We further employed this compact quantum light source in a QKD testbed designed for polarization coding via the BB84 protocol resulting in g^(2)(0) = 0.10±0.01 and a raw key rate of up to (4.72±0.13)kHz using an external laser for excitation. In this setting we investigate the...

A strategy for the design of molecules with large two-photon absorption cross sections, delta, was developed, on the basis of the concept that symmetric charge transfer, from the ends of a conjugated system to the middle, or vice versa, upon excitation is correlated to enhanced values of delta. Synthesized bis(styryl)benzene derivatives with donor-pi-donor, donor-acceptor-donor, and acceptor-donor-acceptor structural motifs exhibit exceptionally large values of delta, up to about 400 times that of trans-stilbene. Quantum chemical calculations performed on these molecules indicate that substantial symmetric charge redistribution occurs upon excitation and provide delta values in good agreement with experimental values. The combination of large delta and high fluorescence quantum yield or triplet yield exhibited by molecules developed here offers potential for unprecedented brightness in two-photon fluorescent imaging or enhanced photosensitivity in two-photon sensitization, respectiv...

Production of a datolite-based heavy concrete for ... SMJ Mortazavi1*, MA Mosleh-Shirazi2, M. Baradaran-Ghahfarokhi3, ... Z. Siavashpour3, A. Farshadi3, M. Ghafoori4, A. Shahvar4 ... 1School of Paramedical Sciences and The Center for Radiological Research, Shiraz ...

PHOTON  /  handshake  or the  spooky action at a distance /
Q:
Why do photons move at all?
In other words, why do photons move away from their source?
#
This is a question that actually probes the very fundamental
principles of modern physics.
. . .  this question really has at its heart the essence,
of what modern physics is really on about.

#
Spooky action at a distance and . . . Photon's  Action ?

What is the significance of this term?
An action is a process that causes a change in a system.
Therefore, an action at a distance is some process
that causes a change at some distance. ( zero distance . . . .  )

What  is the process of  “spooky action at a distance” ?
How fast can be  this  “spooky action at a distance” ?

Can it be instantaneous ?  ( zero distance )

Now we run into a problem when we introduce SRT . . .
define “instantaneous” over any distance and Lorentz
''the principle of locality''
#
An action can only be defined as a local interaction.

''Spooky action at a distance'' is NOT violated  special relativity.
#
The principle of locality is a very important concept in physics.
It is the fundamental reason that light, and photons travel
away from the source.

The fact that actions must be local actually explains
why the fundamental forces must be  . . .  ( zero distance )

The particle - forces as a local action . . .  ( zero distance )

#
Quantum mechanics is a theory of local action, a local interaction
rather than action at a distance . . . but QFT . . . uses  waves . . .
#
The apparent contradiction of quantum mechanics is evident.
#
Quantum mechanics is a local theory.
#
This prompted Einstein’s “spooky action at a distance”
#
The fact that an inherently nonlocal theory describes
only local interactions is one of the hardest things
to understand about quantum theory.
#
1 -  The Quantum nature of Light . . .  The Photoelectric Effect
. . .  Einstein won the Nobel Prize
===

How this principle may be applied to electromagnetism.

Consider an electric field.
An electric field means that there must be  charge
The charges are the source of the field.

Nevertheless, the field is a nonlocal phenomenon
that extends through space away from the charges.
EM fields are nonlocal.
The Lorentz force law tells us that  electron's charge  makes an electric field .

#

Physicists have able to affect the charge by  . . . magnetic field.
, , ,  the change in the  magnetic field will be changed the electric field

#
the space between the charges, the changing field propagates
at the speed of light.
This comes directly from Maxwell’s equations.

#
EM action . . . and Quantum action . . . ?

A photon is a fundamental quantum of an EM field

The entire theory of electromagnetism can be quantized.
The quantum theory of light still satisfies Maxwell’s equations
in the classical limit.

#
The propagation of light with speed (c) away from some source
proves the fact that physics doesn't allow  ''spooky action at a distance''

==========
. . . the solution of Maxwell / Lorentz equation in a vacuum  ( zero distance )
. . . Lorentz ''local time '' at the  zero distance

==============

Classically defininition of position of quantum-particle  between measurements.
-----
How is it possible for Q/p to be at 2 different places at
the same time according to quantum mechanics?
It is not possible.
Quantum mechanics does not say that the Q/p is in two (2) places at once.
What quantum mechanics says is that the Q/p has no classically defined
position at all between measurements.
it has no well-defined position.
The Q-particle is neither here nor there, nor anywhere else.
#
Its position, rather than being represented by a set of numbers
(as in classical mechanics, where the position would be a set of coordinates),
is represented instead by the so-called position operator.
  #
Unlike the numbers, the position operator does not tell us where the Q/p is.
The position operator tells us how likely it is that we find
the Q/p at a particular place.
It does not tell us where the Q/p is.
But when you actually look and find the Q/p somewhere,
the Q/p is in exactly one place: the place where you found it.
It is never in two places at once.

#
Between measurements . . . a free photon / electron can be everywhere
==========
.  Electron Mass value is about 9.1×10^−31 kg . . .
Photon Mass value is about  10^ - 54 kg . . .
Then the  interaction between them at speed  👉299 792 458 m / s 
  would be catastrophic
#
Photons carry mass  by the equation:  m = h*f/c^2
===============

      EPR paradox
https://en.wikipedia.org/wiki/EPR_paradox
My opinion
EPR is an idea about interactions in quantum mechanics
1 - Two photons can interact even they are on opposite sides of
''light-cone'' in ''spacetime''  (if we use modern SRT terminology )
2 - To explain this interaction David Bohm  developed ''the first successful ''
variant  of ''hidden-variable theory, but it had a grossly nonlocal character.''
3 - John Bell suggested  - quantum mechanics interactions could be  local
phenomena  if Bohm's non-local ''hidden-variable''  could be healed by
the . . .  ''the correlations'' 
Bell's '' correlations '' are themselves  variant of paradox.
4 -  The present view of interactions in Quantum mechanics
/ locali or non-local ,  handshake  or  spooky action at a distance /
  is still a matter of debate.
---------

'' He (Bohm) developed an alternative quantum interpretation based
on hidden variables that are nonlocal. A controversial, yet much debated,
theory which also supports the vision of the deep interconnectedness
of the world.''  . . .
. . .  and Bell corrected Bohm's ''hidden variables''  by idea of  ''correlation''
that  is  ''local''  . . .  ''correlation'' is itself a variant of paradox  . . . 
Bohm's ''hidden variables'' were solved by Bell's unknown ''correlations''. . . 
It  is not 'Eureka!' but 'That's funny...''
Quantum problem of interaction: 
handshake or the spooky action at a distance or both.

===============

Spinning particles are simulated by a whirlpool model. Because the momentum P of the spinning particle is proportional to the mass m and the spin frequency ν of the particle, therefore P = Kmν = KmC/λ = mh 0 /λ (where h 0 is named General Planck Constant), De Broglie Wavelength λ = mh 0 /P, and Planck constant h= myyh0 (where myy is the mass of a photon or a Wu's Pair). In addition, De Broglie wavelength, momentum and energy of the electron in Bohr Model are derived. As a result, all Planck constant h in the old formula are replaced by (m e /m yy)h such that in the new version, De Broglie wavelength λ = (m e /m yy)h/P, momentum P = m e (KZe 2)/(nħ)(me/myy) and energy E =-½me(KZe 2) 2 /(n 2 ħ 2) (me/myy) 2. Furthermore, the mass of photon (Wu's Pair) can be derived as m yy = h/h 0 = h/KC (where h 0 is General Planck Constant and K is whirlpool constant).

There has always been a signi cant interest in using optical systems to control quantum phenomena. A major barrier to controllability of quantum optical systems is the fact that the systems are usually in nite dimensional open systems, two cases which have mostly negative controllability results. This thesis develops three new de nitions of controllability and reformulates a previous controllability theorem in order to apply the theorem to the system of interest. Then, the controllability of a pumped dissipative quantum optical cavity with engineered decoherence is investigated using previously developed concepts in quantum control theory, as well as the ones developed in this thesis. Positive controllability results were found for Finite Ensemble Population Controllability and Weak Observable Controllability, while Finite Density Matrix Controllability had a negative result. A result for Strong Observable controllability remains elusive, as the normal nonlinear controllability theo...

We probe the principle of complementarity which is central to quantum mechanics by performing and analyzing a double-slit experiment based on entangled photons created by spontaneous parametric down-conversion due to a pump mode with a coherent double-hump structure (TEM01-mode). In particular, we emphasize the need for a careful selection of the signal-idler photon pairs involved in the corresponding study of visibility and distinguishability. Indeed, when the signal photons interfering at the double slit belong to this double-hump mode we obtain almost perfect visibility of the interference fringes and no which-slit information is available. However, when we break the symmetry between the two maxima of the mode by detecting the entangled idler photon, the paths through the slits become distinguishable and the visibility vanishes. The mode function selected by the detection system decides if interference or which-slit information is accessible in the experiment.

In the present paper, photon frequency shift, e.g. gravitational red and blueshift, is described as the electromagnetic influence from gravity waves on photons, e.g. light waves. Previous reports have described the dynamic electromagnetic processes of the atom, the photon and gravity, and how these characteristics are measured. Results from these reports have been compiled into a theoretical model. The theoretical model describes the mechanism which results in photon frequency shift caused by a gravitational field. The theoretical model gives results similar to General Relativity using Schwarzschild metric. The theoretical model is mapped on black holes.

Tightly focused femtosecond laser pulses of 11-MHz repetition rate and 790-nm wavelength were used to fabricate a set of waveguides in a lithium niobate (LiNbO3) crystal. To establish the inscription conditions for optimal low-loss waveguides, within each sample we varied the laser pulse energy, the speed and direction of translation stage movement, and the focus depth of the laser beam. We deployed two new approaches to enhance the inscription results: 1) increase of the laser pulse energy with increasing focus depth inside the material to compensate for the corresponding decrease of the refractive-index contrast between exposed and unexposed areas, and 2) decrease of the laser energy for the modification tracks closer to the waveguide’s core region to reduce the scattering losses due to high-laser-energy driven waveguide’s non-uniformities. All waveguides had an optical-lattice-like hexagonal packing geometry with a track spacing of 10 μm (optimised for effective suppression of hi...

ABSTRACT We report an experiment in which the correlated imaging in an interferometer with chaotic light can be observed in the intensity pattern rather than the intensity correlation measurement. Similar to ghost imaging with thermal light, object and objective lens are not necessarily set in the same path. Moreover, the two imaging schemes satisfy the same imaging equation. The theoretical analysis shows that the correlated imaging of thermal light is ascribed to the first-order field correlation of the two separate paths, and as a result, it can also be performed through one-photon interference in an incoherent interferometer. Our experiment suggests a phase-sensitive imaging technique using a spatially incoherent light source.

Computation using Monte Carlo simulations is widely used for modelling the light-tissue interaction. Despite this, many of the methods used for building such simulations are poorly described in the literature. In particular, a scheme for translating the scatter angles produced from a phase function into updated photon direction vectors is not explicitly reported. To address this, a method for calculating the change in photon direction following a scattering event is described, thus illuminating one of the fundamental 'building blocks' for researchers developing their own Monte Carlo models. The equations derived in this paper may be readily incorporated into applicable Monte Carlo program code.

High-bit-rate nanocavity-based single photon sources in the 1,550-nm telecom band are challenges facing the development of fibre-based long-haul quantum communication networks. Here we report a very fast single photon source in the 1,550-nm telecom band, which is achieved by a large Purcell enhancement that results from the coupling of a single InAs quantum dot and an InP photonic crystal nanocavity. At a resonance, the spontaneous emission rate was enhanced by a factor of 5 resulting a record fast emission lifetime of 0.2 ns at 1,550 nm. We also demonstrate that this emission exhibits an enhanced anti-bunching dip. This is the first realization of nanocavity-enhanced single photon emitters in the 1,550-nm telecom band. This coupled quantum dot cavity system in the telecom band thus provides a bright high-bit-rate non-classical single photon source that offers appealing novel opportunities for the development of a long-haul quantum telecommunication system via optical fibres.

Dynamical decoupling (DD) is a widely used technique in the framework of nuclear magnetic resonance to protect the coherence of quantum systems against a detrimental environment. DD pulse sequences can be used to enhance the coherence time of quantum memories and the fidelity of quantum gates. However, imperfections of pulses may destroy quantum information or interfere with gate dynamics. We investigate different sequences with respect to their capability to suppress decoherence while still being robust against pulse imperfections in an ion trap experiment. Our results obtained with 171 Yb + ions demonstrate that sequences based on varying phases are self-correcting. We found sequences that allow for the implementation of a conditional quantum gate even if the gate time is more than one order of magnitude longer than the coherence time of the system.

report on the measurement of photon coincidence and photon number statistics of the spontaneous parametric down-converted radiation excited by incoherent pump. A high ratio of photon coincidences in case of multimode acquisition suggests that the present technique may find application in quantum experiments. Experimental and numerical simulation results confirmed that the coincidence ratio in a photon counting ex-periment is tightly coupled to the coherence of the pump beam. An experiment on verification of statistical properties of the down-converted radiation allowed us to evaluate the afterpulse generation probability of the photon counters.

A model of quantum entanglement of electrons is proposed and studied based on Yangton and Yington Theory. Dual Spins and Quantum Entanglement Phase Diagram are developed to explain the transformation between Four Spin Modes during the measurements. "Hidden Variables" (original entanglement quantum states) does exist but can be influenced by the measurements. This result breaks Bell's inequality and supports Einstein's argument in EPR paradox. Quantum Theory maybe is indeed incomplete.

The reactions e + e − → e + e − π 0 X and e + e − → e + e − K 0 S X are studied using data collected at LEP with the L3 detector at centre-of-mass energies between 189 and 202 GeV. Inclusive differential cross sections are measured as a function of the particle transverse momentum p t and the pseudo-rapidity. For p t ≤ 1.5 GeV, the π 0 and K 0 S differential cross sections are described by an exponential, typical of soft hadronic processes. For p t ≥ 1.5 GeV, the cross sections show the presence of perturbative QCD processes, described by a power-law. The data are compared to Monte Carlo predictions and to NLO QCD calculations.

Abstract: Athermal silicon ring resonators are experimentally demonstrated by overlaying a polymer cladding on narrowed silicon wires. The ideal width to achieve athermal condition for the TE mode of 220nm-height SOI waveguides is found to be around 350nm. After overlaying a ...

The high-energy behaviour of the total cross section for highly virtual photons, as predicted by the BFKL equation at next-to-leading order in QCD, is presented. The NLO BFKL predictions, improved by BLM optimal scale setting, are in excellent agreement with recent OPAL and L3 data at CERN LEP2.

Recent advances of type II quasi phase matched (entangled) photon pair sources with Ti:PPLN waveguide, of quantum memories with Ti:Tm:LiNbO 3 waveguide, and of Ti:Tm:LiNbO 3 in-band pumped optical amplifiers (1700 nm < λ < 1900 nm) and lasers are reported.

A complete two-dimensional imaging system based on a silicon monolithic array of 60 single-photon counters is presented. The fabricated solid-state array is rugged and operates at low voltages. Detection efficiency is higher than 40% in the visible range, and cross talk among 50 m pixels is lower than 10 −4. The complete system provides a maximum throughput of 20 kframes/ s with truly parallel readout and nanosecond gating, thanks to the use of an integrated active quenching circuit for each pixel of the array. We report optical and electrical characterizations of the whole imaging system.

We propose a setup that transforms a photon pair in arbitrary rank-four mixed state, which could also be unknown, to a Bell state. The setup involves two linear optical circuits processing the individual photons and a parity gate working with weak cross-Kerr nonlinearity. By the photon number resolving detection on one of the output quantum bus or communication beams, the setup will realize a near deterministic transformation to a Bell state for every entangling attempt. With the simple threshold detectors, on the other hand, the system can still reach a considerable success probability of 50% per try. The decoherence effect caused by photon absorption losses in the operation is also discussed.

We show that transverse engineering of quasi-phase-matched geometries can be used to tailor the spatial mode function that describes the quantum state of photon pairs generated in spontaneous parametric downconversion. We study several geometries and reveal how properly engineered gratings affect, in particular, the spatial correlations embedded in two-photon entangled states.