共查询到20条相似文献,搜索用时 13 毫秒
1.
Laurent Bruneau 《Journal of statistical physics》2014,155(5):888-908
We study the relaxation properties of the quantized electromagnetic field in a cavity under repeated interactions with single two-level atoms, so-called one-atom maser. We improve the ergodic results obtained in Bruneau and Pillet (J Stat Phys 134(5–6):1071–1095, 2009) and prove that, whenever the atoms are initially distributed according to the canonical ensemble at temperature $T>0$ , all the invariant states are mixing. Under some non-resonance condition this invariant state is known to be thermal equilibirum at some renormalized temperature $T^*$ and we prove that the mixing is then arbitrarily slow, in other words that there is no lower bound on the relaxation speed. 相似文献
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Observation of quantum collapse and revival in a one-atom maser 总被引:1,自引:0,他引:1
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The effect of thermal photons on the radiative properties of a one-atom maser is investigated. Stationary Pand Qdistribution functions are determined analytically in the approximation of strong interaction between an atom and a cavity field mode. The generation conditions are found for a one-atom maser. It is shown that taking into account thermal photons leads to a decrease in the threshold value of incoherent pumping. It is demonstrated that generation may occur in the absence of population inversion in the atomic subsystem and when losses exceed the intensity of incoherent pumping. A formula is proposed for the Fano factor of a one-atom maser in the form of the sum of the Fano factors of the microcavity radiation in the absence of thermal photons and the thermal radiation. 相似文献
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The theory of a one-atom maser, when the atoms enter the microresonator being excited to the upper maser level from its ground state by the bichromatic laser field resonant with the two adjacent optically allowed transitions with arbitrary angular momenta, is built. This theory is applied to the investigation of the polarization properties of a one-atom maser, i.e., the dependence of the maser field characteristics on the mutual orientations of the polarization vectors of the maser field mode and of the pump laser field. New experiments are proposed to study such polarization properties, which may be performed within the framework of the experimental setup used by Professor H. Walther and collaborators [1–3]. 相似文献
5.
G. P. Miroshnichenko 《Optics and Spectroscopy》2004,97(3):403-410
The method of periodic trajectories is applied to the analysis of the phase states of a one-atom maser mode, information on which can be obtained from a series of consequent indirect phase-sensitive quantum measurements of atoms leaving the cavity. Such information allows one to study in detail the evolution of a maser mode in a stationary state. The evolution pattern is represented as a random sequence of subensembles in which the mode exists during different time intervals. An approximate stochastic recurrence relation is obtained, which allows us, using the Monte Carlo method, to generate a sequence of relative frequencies of detection of the states of a chosen basis in escaping atoms. Formulas for the phase probability density for subensembles of the mode are derived. These formulas are obtained using as initial data the average relative frequencies measured by an experimenter in a region of a stable trajectory. 相似文献
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The nonlinear dynamics in a paramagnetic maser amplifier is investigated experimentally and theoretically under conditions
such that the active medium exerts a sufficiently strong feedback influence on the pump field to induce population inversion
of the spin levels. Branching of the inversion ratio due to the onset of bistability in the nonlinear microwave cavity of
the pump at a frequency of 150 GHz is observed experimentally. Conditions are determined for the possible excitation of new
nonlinear resonances when the spin system is inverted by a standing-wave field, and the stability of the resulting stationary
nonequilibrium states of the paramagnet is analyzed.
Zh. Tekh. Fiz. 69, 101–105 (May 1999) 相似文献
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Properties of a laser formed by a high-Q cavity and a single incoherently excited atom are studied on the basis of analytical solutions obtained for the quasi-probability P-function. Expressions for the boundaries separating various operating regimes of a one-atom laser (below threshold, above threshold, and self-quenching) are found. It is shown that lasing without inversion and lasing with the decay rate of the excited state exceeding the pump intensity are possible in the system. The degree of coherence of laser radiation is studied. 相似文献
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The multicomponent spectrum of the resonance fluorescence is studied based on the expansion of the Green function with respect to the coherent states for a one-atom laser. An analytical solution is derived for the spectrum in the frequency range corresponding to the vacuum Rabi oscillations in the approximation of the strong atom-field coupling and a low incoherent pump intensity. 相似文献
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One-atom maser 总被引:2,自引:0,他引:2
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Using the method of Einstein coefficients, we derive a quasi-linear kinetic equation for relativistic electrons, in which
synchrotron emission of the particles is taken into account. We discuss the evolution of the electron distribution taking
into account the effect of weak radiative diffusion of the particles over pitch angles. We analyze a solution of the quasi-linear
kinetic equation for electrons and the radiation transfer equation in a stationary thick plasma layer in which maser amplification
of the synchrotron radiation takes place. In this case, we assume that population inversion in the electron distribution and,
thus, stationary synchrotron emission occur due to an external (nonsynchrotron) acceleration mechanism. The efficiency of
this acceleration mechanism is assumed to have a power-law dependence of the electron energy. Under these conditions, we find
the spectra of synchrotron maser emission, which are entirely determined by the external acceleration.
Institute of Applied Physics of the Russian Academy of Sciences, Nizhny Novgorod, Russia. Translated from Izvestiya Vysshikh
Uchebnykh Zavedenii, Radiofizika, Vol. 43, No. 7, pp. 575–594, July, 2000. 相似文献
16.
Electromagnetic emission induced by the injection of spin-polarized electrons from a ferromagnetic material into an n-InSb semiconductor has been obtained. Analysis of the conditions of the excitation of emission and its characteristics indicates that electromagnetic emission is of laser origin. 相似文献
17.
J. L. Hirshfield G. S. Park 《International Journal of Infrared and Millimeter Waves》1991,12(3):275-294
Attention is drawn to an obscure formula derived from relativistic quantum electrodynamics in the mid-'60s by Sokolov and Ternov for induced absorption and emission from highly relativistic electrons in a static uniform magnetic field. From their results, we develop handy formulae and graphs to help in preliminary designs for radiation sources to operate at high synchrotron harmonics. Approximate design parameters are given for 100 kW oscillators operating at wavelengths below 3mm, employing magnetic fields of less than 12 kG. It is shown that the Sokolov-Ternov formula can also be deduced from classical relativistic plasma wave theory, but for a numerical factor in one term. This term is shown to describe a gain mechanism which has apparently received scant notice in the gyrotron literature. 相似文献
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We investigate the possibility of observing parity nonconservation with a metastable hydrogen atom beam, by analyzing two effects which should permit detection of the 2S–2P admixture predicted by the Weinberg model. 相似文献
20.
We calculate P-odd difference of the total cross sections of the deuteron disintegration by left and right polarized photons. The relative magnitude of this difference in the threshold region is about 10−7. Its experimental measurement would give valuable information on the weak nucleon–nucleon interaction at short distances. 相似文献