量子化驻波腔场中缀饰态原子的演化态矢

基于原子与腔场共振相互作用及原子 -场缀饰态 ,建立了两缀饰态原子平移运动Schr dinger方程的一般关系 .然后在对驻波腔场的合适的近似方案下 ,求得了整个原子 -腔场系统的演化波函数 .     

高Q-腔中量子化平移运动与原子内态布居的关系

讨论了在驻波腔场中两能级原子的量子化平移运动与原子内态布居间的相互影响。结果表明原子量子化平移运动敏感地依赖于原子的内态布居。     

量子化驻波腔场中缀饰态原子的演化态矢

基于原子与腔场共振相互作用于原子－场缀饰态，建立了两缀饰态原子平移运动Schrodinger方程的一般关系。然后在对驻波腔场的合适的近似方案下，求得了整个原子－腔场系统的演化波函数。     

非最大量子纠缠信道的量子态传送——在腔QED系统中利用非最大三粒子纠缠GHZ态传送未知原子态

讨论在腔QED中如何利用非最大三粒子纠缠GHZ态实现未知单原子态、两原子纠缠态的概率隐形传送.在量子态传送过程中需要引入一个辅助粒子以解决使用非最大纠缠量子信道导致的态畸变问题.本方案在两原子与腔相互作用的整个过程中,由于经典场同时对两原子进行驱动,量子态的演化不依赖于腔场的态,因而不受腔泄漏和热腔场的影响.     

在腔场中两原子共生纠缠度的变化及最大纠缠态的制备

讨论了两原子与腔场共振相互作用时两原子共生纠缠度(Concurrence)随时间的演化规律.结果表明:通过控制原子和腔场相互作用时间,可制备两原子的最大纠缠态.另外,还考虑了原子自发辐射和腔场衰变对纠缠度的影响.     

利用腔QED实现量子态的转移

利用多个相同的两能级原子在一个强经典场驱动下同时和一个单模腔场发生相互作用模型,给出了如何实现一个量子比特的原子态的远距离转移、原子纠缠态转移的方案.该方案中的腔场处于虚激发状态,原子和腔场之间没有能量交换.因此所提出的态转移方案不受腔场热光子和腔衰减的影响,对腔的Q值要求大大降低,使实验实现成为可能.     

多原子测量和腔中真空单光子组合态的隐形传递

提出了一个隐形传送多量子位真空和单光子叠加纠缠腔场态的方案,通过原子与腔场发生非共振与共振相互作用以及控制原子与腔场相互作用的时间实现非破坏测量和交换信息,发现了通过测量原子的状态识别4个Bell腔场态的方法.     

■型三能级原子纠缠态的制备

研究在热腔场中制备Ξ型三能级原子最大纠缠态的方案.利用多个全同三能级原子同时和一个单模腔场的大失谐相互作用来制备三能级原子最大纠缠态,可忽略腔场热作用和腔延迟作用的影响.文中还研究在热腔场中制备四能级原子最大纠缠态的方案.     

驱动单个原子制备纠缠相干态

提出一种利用经典场驱动单个原子与一个多模腔场相互作用制备腔场的多模纠缠相干态的方案.交替调整原子的跃迁频率,使原子与经典场及多模腔场交替作用,通过对原子的选态测量使多模腔场塌缩为多模纠缠相干态.     

基于原子与腔场谐振相互作用制备原子GHZ态

提出一种利用原子与腔场谐振相互作用制备原子GHZ态的方案。在此方案中,初始时腔场处于真空态,将制备在高能级的三个两能级原子依次注入腔场中发生单光子谐振作用,最后一个制备在低能级的两能级原子注入腔场发生三光子谐振作用。通过对腔场的测量可得到四原子GHZ态。利用该方法原则上可推广得到n个原子GHZ态。     

运动原子的算符压缩效应及腔场统计特性

利用推广的Ｊ－Ｃ模型，研究了理想环形腔中原子的质心运动对原子算符压缩效应及腔场统计特性的影响，当腔场初始处于相干态时，研究结果表明：原子的质心运动将影响光场的光子数分布和光场处于相干态的时间及光场的场熵演化，质心动量的波包越宽，影响越明显；反过来，腔场将影响原子质心的动量分布和原子算符的压缩效应，原子质心运动的波包越宽，对压缩效应的影响越明显。     

双模压缩真空态与运动原子相互作用过程中模间纠缠特性的研究

运用全量子理论,研究双模压缩真空态与运动原子相互作用过程中,双模光场的模间纠缠性质,讨论了原子初态处于激发态时,原子运动和场模结构对模间纠缠性质的影响.结果表明,原子的运动速度和场模结构影响模间纠缠度,但不破坏模间纠缠演化的周期性.     

常压微波等离子体谐振腔的研制及应用

本文报导了一种新型表面波激发微波等(?)于体谐振腔,介绍了谐振腔主要部分的构造和设计要点,并与圆柱形和矩管形谐振腔的基本性能进行了比较,用该谐振腔作光源,研究了常压(?)和氩微波等离子体在原子发射光谱、原子吸收光谱和气相色谱分析法中的应用。     

Coherent control of optical information with matter wave dynamics

In recent years, significant progress has been achieved in manipulating matter with light, and light with matter. Resonant laser fields interacting with cold, dense atom clouds provide a particularly rich system. Such light fields interact strongly with the internal electrons of the atoms, and couple directly to external atomic motion through recoil momenta imparted when photons are absorbed and emitted. Ultraslow light propagation in Bose-Einstein condensates represents an extreme example of resonant light manipulation using cold atoms. Here we demonstrate that a slow light pulse can be stopped and stored in one Bose-Einstein condensate and subsequently revived from a totally different condensate, 160 mum away; information is transferred through conversion of the optical pulse into a travelling matter wave. In the presence of an optical coupling field, a probe laser pulse is first injected into one of the condensates where it is spatially compressed to a length much shorter than the coherent extent of the condensate. The coupling field is then turned off, leaving the atoms in the first condensate in quantum superposition states that comprise a stationary component and a recoiling component in a different internal state. The amplitude and phase of the spatially localized light pulse are imprinted on the recoiling part of the wavefunction, which moves towards the second condensate. When this 'messenger' atom pulse is embedded in the second condensate, the system is re-illuminated with the coupling laser. The probe light is driven back on and the messenger pulse is coherently added to the matter field of the second condensate by way of slow-light-mediated atomic matter-wave amplification. The revived light pulse records the relative amplitude and phase between the recoiling atomic imprint and the revival condensate. Our results provide a dramatic demonstration of coherent optical information processing with matter wave dynamics. Such quantum control may find application in quantum information processing and wavefunction sculpting.     

Attosecond control of electronic processes by intense light fields

The amplitude and frequency of laser light can be routinely measured and controlled on a femtosecond (10(-15) s) timescale. However, in pulses comprising just a few wave cycles, the amplitude envelope and carrier frequency are not sufficient to characterize and control laser radiation, because evolution of the light field is also influenced by a shift of the carrier wave with respect to the pulse peak. This so-called carrier-envelope phase has been predicted and observed to affect strong-field phenomena, but random shot-to-shot shifts have prevented the reproducible guiding of atomic processes using the electric field of light. Here we report the generation of intense, few-cycle laser pulses with a stable carrier envelope phase that permit the triggering and steering of microscopic motion with an ultimate precision limited only by quantum mechanical uncertainty. Using these reproducible light waveforms, we create light-induced atomic currents in ionized matter; the motion of the electronic wave packets can be controlled on timescales shorter than 250 attoseconds (250 x 10(-18) s). This enables us to control the attosecond temporal structure of coherent soft X-ray emission produced by the atomic currents--these X-ray photons provide a sensitive and intuitive tool for determining the carrier-envelope phase.     

Trapping an atom with single photons

The creation of a photon-atom bound state was first envisaged for the case of an atom in a long-lived excited state inside a high-quality microwave cavity. In practice, however, light forces in the microwave domain are insufficient to support an atom against gravity. Although optical photons can provide forces of the required magnitude, atomic decay rates and cavity losses are larger too, and so the atom-cavity system must be continually excited by an external laser. Such an approach also permits continuous observation of the atom's position, by monitoring the light transmitted through the cavity. The dual role of photons in this system distinguishes it from other single-atom experiments such as those using magneto-optical traps, ion traps or a far-off-resonance optical trap. Here we report high-finesse optical cavity experiments in which the change in transmission induced by a single slow atom approaching the cavity triggers an external feedback switch which traps the atom in a light field containing about one photon on average. The oscillatory motion of the trapped atom induces oscillations in the transmitted light intensity; we attribute periodic structure in intensity-correlation-function data to 'long-distance' flights of the atom between different anti-nodes of the standing-wave in the cavity. The system should facilitate investigations of the dynamics of single quantum objects and may find future applications in quantum information processing.     

量子化的大周期驻波场中原子束的折射

研究了一个二能级原子与量子化的大周期驻波场共振相互作用的动力学问题,利用了使演化算符因子化的Wei-Norman方法获得了问题的精确解.对于不同的初始条件,研究了原子束从腔场的折射.