共查询到20条相似文献,搜索用时 15 毫秒
1.
Satish D. Joglekar 《Annals of Physics》1976,101(2):433-450
We discuss the effect of the interactions of transverse photons with nucleons in a nucleus on the energy difference between mirror pairs of nuclei. The inclusion of this interaction energy reduces the coulomb energy anomaly by about 10% in the mirror pairs of nuclei considered. (A = 13 – 33). 相似文献
2.
It is well known that the waveguide beam splitter can be used as a source for the quantum entanglement of photons. The analysis of such quantum entanglement is a difficult problem even for monochromatic photons, since the system under study is multiparametric. This paper will show that quantum entanglement can be represented in a simple form not only for monochromatic photons but also for non-monochromatic ones. It will be shown that quantum entanglement for non-monochromatic photons can be very different from monochromatic photons, which can be used to create large quantum entanglement. 相似文献
3.
4.
G. Abbiendi et al. 《The European Physical Journal C - Particles and Fields》1999,11(3):409-425
The structure of both quasi-real and highly virtual photons is investigated using the reaction , proceeding via the exchange of two photons. The results are based on the complete OPAL dataset taken at centre-of-mass energies close to the mass of the Z boson. The QED structure function and the differential cross-section for quasi-real photons are obtained as functions of the fractional momentum x from the muon momentum which is carried by the struck muon in the quasi-real photon for values of ranging from 1.5 to 400 GeV. The differential cross-section for highly virtual photons is measured for GeV and GeV, where and are the negative values of the four-momentum squared of the two photons such that . Based on azimuthal correlations the QED structure functions and for quasi-real photons are determined for an average of 5.4 GeV.
Received: 8 February 1999 / Published online: 28 September 1999 相似文献
5.
We present a theoretical study of the propagation properties of polarized photons passing through the cavity with an anisotropic metamaterial. We find that the resonant peaks of transmission appear for photons polarized in a certain direction corresponding to a negative element of the permittivity tensor. This indicates the potential for applying such cavity structures as filters for photons with certain polarizations. The resonant peak of transmission for photons having a given frequency can be achieved by adjusting the thicknesses of the air and metamaterial. If the frequency of the incident photons and the thickness of the metamaterial are fixed, the cavity structure can be used as a photon switch controlled by the thickness of the air. The effect of the absorption is considered, and the result shows that the transmission peak always appears, even for metamaterials with large absorption. Finally, the polarization manipulation of such structures is explored. 相似文献
6.
Economical quantum secure direct communication network with single photons 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《中国物理》网站下载免费的PDF全文](/ch/ext_images/free.gif)
In this paper a scheme for quantum secure direct communication
(QSDC) network is proposed with a sequence of polarized single
photons. The single photons are prepared originally in the same
state $\vert 0\rangle$ by the servers on the network, which will
reduce the difficulty for the legitimate users to check
eavesdropping largely. The users code the information on the single
photons with two unitary operations which do not change their
measuring bases. Some decoy photons, which are produced by operating
the sample photons with a Hadamard, are used for preventing a
potentially dishonest server from eavesdropping the quantum lines
freely. This scheme is an economical one as it is the easiest way
for QSDC network communication securely. 相似文献
7.
C. M. B. Monteiro L. M. P. Fernandes J. A. M. Lopes J. F. C. A. Veloso J. M. F. Dos Santos 《Applied physics. B, Lasers and optics》2005,81(4):531-535
The room-temperature response of large-area avalanche photodiodes (LAAPDs) to 128- and 172-nm light pulses is investigated. The minimum detectable number of photons, which can produce a signal just above the noise level, is found to be around 1300 and 600 photons, respectively. The LAAPD relative statistical fluctuations in the detection of 15 000 photons of 128 nm and 25 500 photons of 172 nm were found to be about 3.9% and 2.2%, respectively. Both the minimum detectable number of photons and statistical fluctuations do not depend on the photon wavelength, but rather on the number of charge carriers produced by the light pulse in the LAAPD. For these light levels, good LAAPD performance is already achieved for gains as low as 30 to 60. 相似文献
8.
Corona discharge is a self-sustained discharge which appears at electrodes with a small radius curvature in gas insulation. An almost invisible glow occurs just above the inception voltage. Corona phenomenon is mainly used in electro-technological processes to obtain space charge for electrostatic precipitation, separation of different particles, electrostatic liquid or solid coating, neutralization of space charge, etc. All of these processes rely on a strong nonhomogeneous electric field generated by a point – plate electrode system. When the critical value of the applied voltage is reached, the ionization processes near the point electrode start and give rise to the current between two electrodes. If the pointed electrode is positive, it is possible to observe an anomaly of the current – voltage (I-U) characteristic for the point-plate space. It means that while the voltage is raising the current density decreases in a narrow voltage area (2–3 kV). The anomaly was technically named as negative differential conductivity (dI/dU < 0). Unstable current can have a negative influence on electro-technological processes. The anomaly was detected for different shapes and materials of the electrode as well as for various temperatures and distances between electrodes. An oxidation layer, which appears on the metal electrode, also influences the ionization processes near the pointed electrode and causes a decrease of a current. In this paper measuring of the discharge activity in a point – plate electrode system is presented. Ionization of gas atoms and molecules in a high electric field and the following recombination of electrons and positive ions in the corona region can give rise to high-energy photons which produce new electrons in the field of discharge. Corona discharges are detected by DayCor Corona camera which can register UV emission generated by corona in a day light. The experiment was conducted with various shapes of the pointed electrode and distances between the high voltage and the grounded electrode under applied direct voltage with positive and negative polarity. 相似文献
9.
R. M. Feshchenko A. V. Vinogradov 《Journal of Experimental and Theoretical Physics》2018,127(2):274-278
Relations determining the number of photons in an electromagnetic field are considered from the point of view of a classical electromagnetic field. A relativistically invariant expression is obtained for the number of emitted photons in terms of charges and currents producing the electromagnetic field. Examples are considered for calculating the numbers of photons in the electromagnetic field for the case of the electric dipole radiation field, as well as the field of a finite and spatially restricted electromagnetic pulse. 相似文献
10.
Based on the facility of the Shanghai Laser Electron Gamma Source (SLEGS), the transmutation for nuclear wastes such as 137Cs and 129I is investigated. It is found that nuclear waste can be transmuted efficiently via photonuclear reaction triggered by gamma photons generated from Compton backscattering between CO2 laser photons and 3.5 GeV electrons. The nuclear activities of 137Cs and 129I are evaluated and compared with the results of transmutation triggered by bremsstrahlung gamma photons driven by ultra intense laser. Due to the better character of gamma photon spectrum as well as the high brightness of gamma photons, the transmutation rate of Compton backscattering method is much higher than that of the bremsstrahlung method. 相似文献
11.
12.
Transmutation of nuclear wastes using photonuclear reactions triggered by Compton backscattering photons at the Shanghai laser electrongamma source
下载免费PDF全文
![点击此处可从《中国物理C(英文版)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
CHEN Jin-Gen XU Wang WANG Hong-Wei GUO Wei MA Yu-Gang CAI Xiang-Zhou LU Guang-Cheng XU Yi PAN Qiang-Yan YUAN Ren-Yong XU Jia-Qiang YAN Zhe FAN Gong-Tao SHEN Wen-Qing 《中国物理C(英文版)》2008,32(8):677-680
Based on the facility of the Shanghai Laser Electron Gamma Source (SLEGS),the transmutation for nuclear wastes such as 137Cs and 129I is investigated.It is found that nuclear waste can be transmuted efficiently via photonuclear reaction triggered by gamma photons generated from Compton backscattering between CO2 laser photons and 3.5 GeV electrons.The nuclear activities of 137Cs and 129I are evaluated and compared with the results of transmutation triggered by bremsstrahlung gamma photons driven by ultra intense laser.Due to the better character of gamma photon spectrum as well as the high brightness of gamma photons,the transmutation rate of Compton backscattering method is much higher than that of the bremsstrahlung method. 相似文献
13.
With Rytov approximation and Kolmogorov spectrum model of index-of-refraction fluctuation, we study the effects of turbulence aberration on the orbital angular momentum of single photons in atmospheric communication channel. A theoretical model of measurement probabilities of orbital angular momentum states for single photons propagation under the Zernike tilt corrected slant path turbulent atmosphere channel is established. Our research shows that tilt-corrected residual aberration not only damage the initial OAM, but also induce new OAM. With the increasing of D/ρ0, the number of the initial OAM photons will go down while the effective number of new OAM ascends. Meanwhile, the receiving probability of initial OAM photons declines, as the turbulence shifts from weak to strong. For Zernike tilt-corrected residual aberration, the receiving probability of initial OAM photons declines as the diameter of detector increases. The effect of Zernike tilt-corrected residual aberration on OAM of the photons is more larger than the effect of Zernike tilt turbulent aberration. 相似文献
14.
Mladen Pavičić 《International Journal of Theoretical Physics》1995,34(8):1653-1665
It is shown that one canpreselect with certainty photons in the singlet state from a set of completely unpolarized and independent photons which did not in any way directly interact with each other-without in any way affecting them. The result is based on an experiment which puts together two unpolarized photons from two independent singlet pairs, making them interfere in the fourth order at a beam splitter so as to preselect the singlet state of the other two photons from the pairs, although no polarization measurement has been carried out on the photons coming out from the beam splitter. One can obtain the expectation value for the correlated state of the former two unpolarized photons in the Hilbert space and therefore write down the singlet state for them, but one apparently cannotinfer the state within the Hilbert space. This might suggest that the Hilbert space is not amaximal model for quantum measurements. 相似文献
15.
The convergence of the nuclear field theory is studied for situations in which the interaction energy between the photons is of the same order of magnitude as the correlation energy of the photons. 相似文献
16.
We propose two schemes for realizing quantum secure direct communication (QSDC) by using a set of ordered two-photon three-dimensional hyperentangled states entangled in two degrees of freedom (DOFs) as quantum information channels. In the first scheme, the photons from Bob to Alice are transmitted only once. After insuring the security of the quantum channels, Bob encodes the secret message on his photons. Then Alice performs single-photon two-DOF Bell bases measurements on her photons. This scheme has better security than former QSDC protocols. In the second scheme, Bob transmits photons to Alice twice. After insuring the security of the quantum channels, Bob encodes the secret message on his photons. Then Alice performs two-photon Bell bases measurements on each DOF. The scheme has more information capacity than former QSDC protocols. 相似文献
17.
We experimentally demonstrate sum-frequency generation with entangled photon pairs, generating as many as 40,000 photons per second, visible even to the naked eye. The nonclassical nature of the interaction is exhibited by a linear intensity dependence of the nonlinear process. The key element in our scheme is the generation of an ultrahigh flux of entangled photons while maintaining their nonclassical properties. This is made possible by generating the down-converted photons as broadband as possible, orders of magnitude wider than the pump. This approach can be applied to other nonlinear interactions, and may become useful for various quantum-measurement tasks. 相似文献
18.
Claes R. Cramer 《General Relativity and Gravitation》1997,29(4):445-454
We extend the study of the possible use of the Schwarzschild black hole as a gravitational mirror to the more general case of an uncharged Kerr black hole. We use the null geodesic equation in the equatorial plane to prove a theorem concerning the conditions the impact parameter has to satisfy if boomerang photons are to exist. We derive an equation for these boomerang photons and an equation for the emission angle. Finally, the radial null geodesic equation is integrated numerically in order to illustrate boomerang photons. 相似文献
19.
M. A. Garasyov E. V. Derishev Vl. V. Kocharovsky 《Radiophysics and Quantum Electronics》2011,53(12):679-687
We numerically model the frequency redistribution of gyroresonant photons in a plane-parallel semi-infinite plasma atmosphere
of a compact star by means of the Monte-Carlo method. We calculate the mean frequency shift and the mean number of scatterings
for photons leaving the atmosphere as functions of the optical depth at emission, plasma temperature, and magnetic field strength.
The probability of the escape of cyclotron-radiation photons from the atmosphere as a function of their optical depth at birth
is calculated. The influence of the frequency redistribution effects on the spectrum of emergent radiation is studied. 相似文献
20.
The (e, e'γ) coincidence cross section is expressed in terms of the nuclear polarizabilities as a generalization of the standard (γ, γ') formalism for polarized photons. This formalism is well suited to determine nuclear spins in a model-independent way. Due to the presence of virtual photons of longitudinal and transverse polarization and variable momentum transfer, electroexcitation gives more complete information than scattering of real photons and allows one to study the polarizabilities as function of excitation energy and momentum transfer. 相似文献