共查询到20条相似文献,搜索用时 140 毫秒
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A. V. Koshelkin 《Journal of Experimental and Theoretical Physics》2003,96(4):653-657
On the basis of diagram formalism for two-particle Green functions, the bremsstrahlung of charged particles interacting in a dense medium is investigated. In the case of production of soft photons, exact expressions for two-particle Green functions corresponding to the process of particle bremsstrahlung in the substance are obtained. The Green functions found are fully determined by the set of closed irreducible diagrams. It is shown that, in the case of radiation in a sufficiently dense medium in a far long-wave region of the spectrum, the coherent multiple particle scattering results in an additional (as compared that reported earlier in [1–13]) suppression of the bremsstrahlung photon yield. 相似文献
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Slow light supported by electromagnetically induced transparency effect in dispersive medium is extremely susceptible with respect to Doppler detuning.In this paper,the Doppler effect induced by rotating dispersive medium was considered and the effect of the velocity of rotating dispersive medium on the group velocity was studied.Based on a dispersive slow-light medium,a high sensitive optical rotation sensor for measuring absolute rotation is proposed and analysed.The sensitivity of the rotation sensor is the group delay between the counterpropagationed wave packets in the device,and scales directly with square of the group index which can reach 10 2-10 8 orders of magnitude by selecting a proper dispersive medium. 相似文献
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A. V. Kozlovskii 《Journal of Experimental and Theoretical Physics》2001,93(3):462-470
The interaction of a two-level atom uniformly moving along a classical trajectory with a high-Q cavity quantum mode is analyzed. The dressed-state method is used to derive a recurrence formula for the transition probability of the atom with photon emission; the temporal dynamics of this probability qualitatively depends on the Doppler shift of the atomic transition frequency, on the Rabi frequency of the atom-field system, and on the detuning of the atomic transition frequency from the field mode frequency. The emission dynamics of a moving atom is very sensitive to the detuning. Rabi-type oscillations with a frequency equal to the Doppler shift can arise under certain conditions. At resonance, the emission probability of a moving atom can considerably exceed the emission probability of an atom at rest. A plane-parallel-mirror cavity and a confocal spherical-mirror cavity are considered. It is shown that the peculiarities of Doppler-Rabi oscillations must be taken into account in micromaser theory. 相似文献
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Wilson CM Duty T Sandberg M Persson F Shumeiko V Delsing P 《Physical review letters》2010,105(23):233907
We report the observation of photon generation in a microwave cavity with a time-dependent boundary condition. Our system is a microfabricated quarter-wave coplanar waveguide cavity. The electrical length of the cavity is varied by using the tunable inductance of a superconducting quantum interference device. It is measured at a temperature significantly less than the resonance frequency. When the length is modulated at approximately twice the static resonance frequency, spontaneous parametric oscillations of the cavity field are observed. Time-resolved measurements of the dynamical state of the cavity show multiple stable states. The behavior is well described by theory. Our results may be considered a preliminary step towards demonstrating the dynamical Casimir effect. 相似文献
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A. M. Basharov N. V. Znamenskii A. Yu. Shashkov 《Bulletin of the Russian Academy of Sciences: Physics》2008,72(5):670-672
The superradiance, photon echo, and coherence transformation in three-level cascade-type atoms have been theoretically investigated for the case where the frequency of an optically allowed transition from the upper level coincides with the cavity frequency. 相似文献
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We have established the master equation for the micromaser with a Kerr medium,we have studied the photon statics of the micromaser with a Kerr medium field and analysed the influence of the Kerr effect on the photon statistics,The influence of the Kerr effect on the photon statistics is different in two regimes,In the thermal-atom regime,the Kerr effect produces quantum noise,and decreases the mean photon number.In the ultracold-atom regime,with the increase of the nonlinear parameter of the Kerr medium,the stability of the mean photon number and the normalized variance enhances the mean photon number,and the normalized variance exhibits collapse-revival phenomena periodically,their resonance peaks become lower,and the photon statistics of more and more regions are sub-Poissonian. 相似文献
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A. V. Koshelkin 《JETP Letters》1996,63(12):958-962
Photon production by scalar particles undergoing multiple elastic collisions with isotropically scattering centers in matter
is investigated. It is shown that soft-photon production is a transition-radiation process at the boundary between vacuum
and an ideal conductor.
Pis’ma Zh. éksp. Teor. Fiz. 63, No. 12, 911–914 (25 June 1996) 相似文献
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Chernomordik V Gandjbakhche AH Hassan M Pajevic S Weiss GH 《Optics Communications》2010,283(23):4832-4839
We develop an analytic model of time-resolved fluorescent imaging of photons migrating through a semi-infinite turbid medium bounded by an infinite plane in the presence of a single stationary point fluorophore embedded in the medium. In contrast to earlier models of fluorescent imaging in which photon motion is assumed to be some form of continuous diffusion process, the present analysis is based on a continuous-time random walk (CTRW) on a simple cubic lattice, the objective being to estimate the position and lifetime of the fluorophore. This can provide information related to local variations in pH and temperature with potential medical significance. Aspects of the theory were tested using time-resolved measurements of the fluorescence from small inclusions inside tissue-like phantoms. The experimental results were found to be in good agreement with theoretical predictions provided that the fluorophore was not located too close to the planar boundary, a common problem in many diffusive systems. 相似文献
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Kreuter A Becher C Lancaster GP Mundt AB Russo C Häffner H Roos C Eschner J Schmidt-Kaler F Blatt R 《Physical review letters》2004,92(20):203002
We investigate the spontaneous emission lifetime of a single trapped (40)Ca+ ion placed at different positions in the vacuum standing wave inside a high finesse cavity which is stabilized to the atomic transition. The lifetime is measured by quantum state detection after pi-pulse excitation. The result for the natural lifetime of the D(5/2) metastable state of 1161(22) ms agrees, within 1 standard deviation, with the most precise published value. We observe a reduction of the spontaneous emission lifetime of approximately 15% in the node of the vacuum field. 相似文献
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本文用密度算符方法研究了级联工能级原子同单膜腔场的相互作用,求得了辐射场的光子数几率分布,并讨论了反聚束效应和不同偏调的影响. 相似文献
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