共查询到20条相似文献,搜索用时 15 毫秒
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We investigate the effects of an external magnetic field in the gap structure of a color superconductor with three massless quark flavors. Using an effective theory with four-fermion interactions, inspired by one-gluon exchange, we show that the long-range component B of the external magnetic field that penetrates the color-flavor locked phase modifies its gap structure, producing a new phase of lower symmetry. A main outcome of our study is that the B field tends to strengthen the gaps formed by Q-charged and Q-neutral quarks that coupled among themselves through tree-level vertices. These gaps are enhanced by the field-dependent density of states of the Q-charged quarks on the Fermi surface. Our considerations are relevant for the study of highly magnetized compact stars. 相似文献
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Angular-multiplexed hologram recording in iron-doped lithium niobate crystals was carried out with near-infrared light. An incremental recording schedule with active phase locking of the light pattern onto the hologram was used. Continuous and reproducible recording of holograms of equal efficiency was achieved, and a hologram multiplexing number, M/#=2 , for a 5-mm-thick crystal was obtained at a 760-nm wavelength of light. 相似文献
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We study pseudoscalar meson excitations in the color-flavor locked phase in a Nambu-Jona-Lasinio (NJL) model by calculating
diquark loops.
The text was submitted by the authors in English. 相似文献
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We demonstrate that quark matter in the color-flavor locked phase of QCD is rigorously electrically neutral, despite the unequal quark masses, and even in the presence of an electron chemical potential. As long as the strange quark mass and the electron chemical potential do not preclude the color-flavor locked phase, quark matter is automatically neutral. No electrons are required and none are admitted. 相似文献
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The superconductivity in cold dense QCD with three massless flavors is analyzed in the framework of the Schwinger-Dyson equation. The set of two coupled gap equations for the color antitriplet, flavor antitriplet
and the color sextet, flavor sextet (6,6) order parameters is derived. It is shown that the antitriplet-antitriplet gives the dominant contribution to the color-flavor locked order parameter, while the sextet-sextet is small but nonzero. 相似文献
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We propose a five-dimensional framework for modeling low-energy properties of QCD. In the simplest three parameter model we compute masses, decay rates and couplings of the lightest mesons. The model fits experimental data to within 10%. The framework is a holographic version of the QCD sum rules, motivated by the anti-de Sitter/conformal field theory correspondence. The model naturally incorporates properties of QCD dictated by chiral symmetry, which we demonstrate by deriving the Gell-Mann-Oakes-Renner relationship for the pion mass. 相似文献
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Longtin A 《Chaos (Woodbury, N.Y.)》1995,5(1):209-215
Periodically driven nonlinear oscillators can exhibit a form of phase locking in which a well-defined feature of the motion occurs near a preferred phase of the stimulus, but a random number of stimulus cycles are skipped between its occurrences. This feature may be an action potential, or another crossing by a state variable of some specific value. This behavior can also occur when no apparent external periodic forcing is present. The phase preference is then measured with respect to a time scale internal to the system. Models of these behaviors are briefly reviewed, and new mechanisms are presented that involve the coupling of noise to the equations of motion. Our study investigates such stochastic phase locking near bifurcations commonly present in models of biological oscillators: (1) a supercritical and (2) a subcritical Hopf bifurcation, and, under autonomous conditions, near (3) a saddle-node bifurcation, and (4) chaotic behavior. Our results complement previous studies of aperiodic phase locking in which noise perturbs deterministic phase-locked motion. In our study however, we emphasize how noise can induce a stochastic phase-locked motion that does not have a similar deterministic counterpart. Although our study focuses on models of excitable and bursting neurons, our results are applicable to other oscillators, such as those discussed in the respiratory and cardiac literatures. (c) 1995 American Institute of Physics. 相似文献
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Zhen-Bin Zhang Ru-Juan Jia Jasmina Tekić Yang Yang Cang-Long Wang Jia-Wei Li Xiao-Yun Wang Wen-Shan Duan Lei Yang 《Frontiers of Physics》2015,10(4):100506
Rectification phenomena and the phase locking in a two-dimensional overdamped Frenkel–Kontorova model with a graphite periodic substrate were studied. The presence of dc and ac forces in the longitudinal direction causes the appearance of dynamicalmode locking and the steps in the response function of the system. On the other hand, the presence of an ac force in the transverse direction causes the appearance of rectification, even though there is no net dc force in the transverse direction. It is found that whereas the longitudinal velocity increases in a series of steps, rectification in the transverse direction can occur only between two neighbor steps. The amplitude and phase of the external ac driving force affect the depinning force, rectification of the system and particles trajectories. 相似文献
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本文报道了一项称为载波相移全息干涉计量的自动相位估算的新技术。该技术的主要特点是不同相移的条纹图案可用双曝光全息重视。这样即可用来对与时间相关的问题进行自动相位估算。 相似文献
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《中国光学快报(英文版)》2016,(1)
We present a polarization-multiplexing off-axis Mach–Zehnder configuration for dual-wavelength digital holography to achieve phase imaging in one shot. In this configuration, two orthogonal linear-polarized waves with respect to different wavelengths are employed to record respective holograms synchronously, where two recording waves transmit independently through the same optical paths of the interferometer, and by installing two analyzer polarizers each to filter off either of two wavelengths, and filtering through the other, the holograms are acquired, respectively, by a pair of CCDs at the same time. The unwrapped phase image of a grating with groove depth 7.1 μm is retrieved via spatial frequency filtering. 相似文献
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Phase conjugation of singular (vortex) beams is performed using a static nonlinearly recorded hologram. The diagnostics of phase-conjugate optical vortices is carried out by an original method based on the Young model of diffraction phenomena. It is shown that a phase-conjugate vortex is characterized by the same topological charge as a vortex inverted by degenerate four wave mixing, differing in sign from a vortex reflected by an ordinary mirror. 相似文献
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B. Frank K.Y. Platov W. Krech 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,5(2):187-192
The synchronization properties of a simple two-dimensional Josephson array consisting of two coupled SQUID cells are studied
within the Werthamer as well as the RCSJ model. Special emphasis is placed on the role of inductances arranged perpendicular
and parallel to the current bias direction for the phase locking behavior. The general behavior within the Werthamer model
is found to be similar to that within the RCSJ model. However, there are quantitative differences, e.g. an enhanced phase shift between the voltage oscillations within one cell and a shift of the parameter range for the in-phase
regime between different cells towards lower values of the McCumber parameter in the Werthamer model.
Received: 23 March 1998 / Revised: 3 June 1998 / Accepted: 9 June 1998 相似文献