共查询到20条相似文献,搜索用时 46 毫秒
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1forionTrappingoftwoatotnsor.ionsatsmallinteratondcdistancesenablesonetOobservecollectivephenomenaandinterferenceinthefluorescencefi.ld['J-Atsmallinteratdricdistanestheendssdrifr0meachi0ninterfereswtththeothersinawaydependingontheinitialphaseoftheatondcdipoesandtheresultingradiationiseitherreduced0renhanced.Eichmannetal.[2]haVobservdtheMtyPeinterferenceinthenuoresencefield0ftW0traPpedionsWhicharecontinuoulydrivenbyaweakcoherentlaserfield,andshawnthattheinterferencepatterndePendsnotonlyonthe… 相似文献
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In this paper, we derive the time dependent solution of the effective master equation for the reduced density matrix operator of a two level atom driven by a coherent laser field and damped by a finite bandwidth squeezed vacuum. The results show that the initial state setting, detuning parameter and Rabi frequency play important roles in the evolution of the system dynamics and geometric phase. We present a useful way for controlling the geometric phase variation for the system under consideration. 相似文献
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We study the absorption spectrum of a two-level atom driven by a resonant laser field and damped by a broadband squeezed vacuum. We show that for some values of the Rabi frequency of the driving field the central component of the absorption spectrum can switch from absorption to amplification. We find that the presence of the squeezed vacuum field is essential for the gain at the central component. Moreover, the gain is not attributed to any population inversion in both the atomic bare states and in the dressed atomic states. We show that the gain originates from the coherent population oscillations, which are significantly enhanced when the atom is damped by a broadband squeezed vacuum. 相似文献
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耦合双原子Jaynes-Cummings模型的腔场谱H 总被引:14,自引:8,他引:6
研究了处于激发态的两原子与高Q腔场相互作用单光子过程的腔场谱,给出了初始光场为光子数态、相干态、压缩真空态时的腔场谱数值计算结果,分析了原子间偶极-偶极相互作用强度gα对腔场谱结构的影响.发现真空场Rabi峰,当gα较弱时为4峰,gα较强时为3峰结构;弱场数态(n>0)时为5峰,强场时为3峰结构.相干态和压缩真空态时,谱结构与光子数分布有关,一般为复杂的多峰结构.结果表明,gα对峰位峰高都有影响,破坏了谱结构的对称性,但这种影响只在真空场和弱场时才较明显. 相似文献
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叠加激发双模压缩真空态的量子统计特性(英文) 总被引:5,自引:3,他引:2
从激发双模压缩真空态a+mb+m|ξ>出发构造了叠加态|Ψ>,研究了|Ψ>的量子统计特性.结果表明:在一定的条件下,随着相位差的变化,叠加态|Ψ>的平均光子数出现类似于Rabi振荡的崩塌与复原现象,而且与单个激发双模压缩真空态a+mb+m|ξ>相比,在叠加态|Ψ>中光场的相位压缩和亚泊松光子统计特性都得到了加强. 相似文献
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Vahlbruch H Chelkowski S Hage B Franzen A Danzmann K Schnabel R 《Physical review letters》2006,97(1):011101
We propose and demonstrate a coherent control scheme for stable phase locking of squeezed vacuum fields. We focus on sideband fields at frequencies from 10 Hz to 10 kHz, which is a frequency regime of particular interest in gravitational-wave detection and for which conventional control schemes have failed so far. A vacuum field with broadband squeezing covering this entire band was produced using optical parametric oscillation and characterized with balanced homodyne detection. The system was stably controlled over long periods utilizing two coherent but frequency shifted control fields. In order to demonstrate the performance of our setup the squeezed field was used for a nonclassical sensitivity improvement of a Michelson interferometer at audio frequencies. 相似文献
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We introduce a scheme for creating continuous variable entanglement between an atomic beam and an optical field, by using squeezed light to outcouple atoms from a Bose-Einstein condensate via a Raman transition. We model the full multimode dynamics of the atom laser beam and the squeezed optical field and show that, with appropriate two-photon detuning and two-photon Rabi frequency, the transmitted light is entangled in amplitude and phase with the outcoupled atom laser beam. The degree of entanglement is controllable via changes in the two-photon Rabi frequency of the outcoupling process. 相似文献
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叠加多模薛定谔猫态纠缠光场的不等幂次高次差压缩 总被引:1,自引:1,他引:0
利用多模压缩态理论研究了由多模复共轭相干态、多模复共轭虚相干态和多模真空态的线性叠加所组成的三态叠加多模薛定谔猫态纠缠光场的广义非线性不等幂次高次差压缩特性.结果发现:①真空场对此猫态光场的不等幂次高次差压缩效应没有影响;②在一定条件下,此猫态光场的两个正交相位分量可分别呈现出不等幂次高次差压缩效应;③而在另外的条件下,此猫态光场的两个正交相位分量则可同时出现上述的不等幂次高次差压缩效应,这是一种与测不准关系相悖的现象,称此种现象为"双边差压缩"效应. 相似文献
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利用低频光通信波段真空压缩态光场可实现基于光纤的量子精密测量.本文利用简并光学参量振荡器实验制备出1550 nm低频真空压缩态光场.在分析频段10—500 kHz范围内压缩态光场的压缩度均达3 dB.用实验制备的1550 nm真空压缩态光场填补光纤马赫-曾德尔干涉仪的真空通道,实现了量子增强型光纤马赫-曾德尔干涉仪,完成了突破标准量子极限的相位调制频率为500 kHz的低频信号测量.与光纤马赫-曾德尔干涉仪相比,测量信噪比提高了2 dB. 相似文献
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We have studied the spontaneous emission behaviour in a five-level M-type atom driven by two optical fields of high frequencies and a microwave field of low-frequency. In absence of non-orthogonal decaying pathways, due to microwave field induced low-frequency coherence, the present model produces the emission spectrum resembling that of a three-level system controlled by the effect of vacuum induced decay-interference. For particular sets of values of the Rabi frequencies of the resonant coherent fields, the system exhibits quantum interference induced switching effect. By using this model, we have shown that the phenomenon of narrowing can be induced in the emission peaks without any detuning and phase control of the coherent fields. With the increase in the value of the Rabi frequency of the microwave field, this feature will be accompanied by the peak-compression and -repulsion effect. When the coherent fields are far from resonance, the appearance of the single-photon and the two-photon peaks in the emission spectrum can be easily controlled by changing the value of the Rabi frequency of the microwave field. We have shown the appearance of multiple dark regions in the emission line shape for equal as well as unequal decay rates of two emission pathways. Other interesting phenomena like elimination, enhancement and suppression of spectral line are also explored in various resonant and non-resonant cases. 相似文献
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《Optics Communications》1987,64(6):523-528
The weak probe-field absorption spectrum of a two level atom driven by a coherent pump field in a squeezed vacuum is calculated. When the squeezed light and coherent driving field are tuned to atomic resonance, the absorption spectrum of the probe field can show a linewidth smaller than the linewidth in normal vacuum. 相似文献
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We use the vacuum Rabi splitting to perform quantum nondemolition measurements that prepare a conditionally spin squeezed state of a collective atomic psuedospin. We infer a 3.4(6) dB improvement in quantum phase estimation relative to the standard quantum limit for a coherent spin state composed of uncorrelated atoms. The measured collective spin is composed of the two-level clock states of nearly 10(6) (87)Rb atoms confined inside a low finesse F=710 optical cavity. This technique may improve atomic sensor precision and/or bandwidth, and may lead to more precise tests of fundamental physics. 相似文献
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Kerr介质腔中非线性J-C模型的腔场谱 总被引:2,自引:2,他引:0
研究了Kerr介质腔中非线性J-C模型的腔场谱.导出了初始光场处于任意量子态时腔场谱的计算公式,给出了光场处于数态、相干态和压缩真空态时的数值结果,讨论了Kerr效应和初始场强对腔场谱的影响.发现在光子数态的情况下,n≠1时均为2峰结构,Kerr介质使得中心频率按x(2n-1)的规律向高频方向移动,并破坏谱结构的双峰对称性;在相干态和压缩真空态情况下,当Kerr效应较弱时,非线性J-C模型中腔场谱的非经典特性较为突出,Kerr效应较强时,呈现多峰结构,谱的结构特征主要由Kerr效应决定,由于原子与腔场的耦合被抑制,腔场谱的非线性特征趋于消失. 相似文献
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