共查询到18条相似文献,搜索用时 234 毫秒
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卢道明 《原子与分子物理学报》2010,27(1):113-116
利用时间演化算符方法研究了K模相干光场与二能级原子相互作用系统中系统态矢的演化.利用数值计算方法研究了三模相干光场与二能级原子相互作用系统中场熵的演化,讨论了初始光场强度对场熵演化的影响.结果表明:当初始光场较强时,场熵随时间的演化呈现出规则的振荡,光场与原子之间的相互作用主要表现为双光子跃迁过程. 相似文献
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对相干态与级联三能级原子相互作用过程中原子与场的动力学特性 总被引:5,自引:1,他引:4
研究对相干态与级联三能原子相互作用的动力学特性。结果表明,无论场模与原子的中间能级是否失谐,拉比振荡和互关联函数的时间演化都呈现崩溃与回复现象,但崩溃的持续时间随失谐量的增加而迅速延长,且两模之间随时间的演化即出现关联也出现反关联。 相似文献
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T-C模型中纠缠原子与相干态光场相互作用平均光子数的演化 总被引:1,自引:1,他引:1
研究了一对纠缠的二能级原子与单模相干态光场的相互作用,得出平均光子数随时间的演化规律.讨论了相干振幅分量模平方|α|2、原子-场的耦合系数g、原子间的耦合系数ε及纠缠因子cosθ对光场的平均光子数的〈n(t)〉的影响,结果表明:随着相干振幅分量模平方,原子-场的耦合系数,原子间的耦合系数的变化,平均光子数演化曲线的平均值和系统量子崩塌-复苏的周期都会随之变化.但纠缠因子的变化并不影响量子崩塌-复苏的周期,只是使平均光子数随时间演化的值慢慢变化. 相似文献
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本文应用negativity和concurrence两种纠缠度量标准,考察了双原子与双模光场相互作用系统中,原子间纠缠和光场模间纠缠随时间的演化规律,发现它们在时间演化过程中可以相互转换,在一定条件下两者具有很好的对应关系;对于两量子位系统,negativity和concurrence的取值范围一样,在判断纠缠存在与否的标准上也完全相同,但当系统处于混态时二者的大小不能始终保持一致.
关键词:
量子纠缠
negetivity
concurrence
双原子
双模光场 相似文献
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在旋波近似下,同时考虑原子运动和光场频率随时间作正弦函数变化,研究了二能级原子与单模辐射场相互作用系统中场的量子约化熵的演化规律.运用数值计算的方法分别给出了在不考虑原子的运动和考虑原子的运动的情况下场熵随时间的演化曲线,讨论了原子运动、场模结构、场频率的幅值和角频率变化对场熵的影响.根据Schmidt分解定理,解析制备了光场与原子的纠缠态、光场偶数态及原子相干叠加态,获得了调控和制备上述量子态的系统参量.研究结果表明:场熵的演化受场频率变化的调制,场频率变化的幅值增大会削弱场与原子的相互作用,场熵演化的周期性与场频率变化一致|原子的运动导致了场熵演化周期加倍|在场频率变化的角频率一定的情形下,场熵演化规律与场模结构参量的奇偶性有关|无论原子运动与否,都可周期性制备场-原子的近似EPR态. 相似文献
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利用Jaynes-Cummings模型,考虑场频率受微扰的情况,在旋波近似下研究了二能级原子与单模辐射场相互作用系统中量子态保真度的演化.利用数值计算方法给出量子态保真度随时间的演化曲线.研究了场频率随时间正弦函数形式变化对系统、光场和原子的量子态保真度演化的影响.结果表明:场频率随时间正弦函数形式变化对系统和光场的量子态保真度的演化的影响很小,但对原子的量子态保真度的演化有显著影响. 相似文献
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研究了二项式光场和负二项式光场与耦合双原子依赖强度耦合相互作用系统原子布居反转的时间演化规律,讨论了原子间相互作用和光场初态对原子反转的时间演化的影响. 相似文献
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P.D. Drummond 《Optics Communications》1982,40(3):224-228
The time-evolution of an optically bistable interferometer is obtained using adiabatic elimination of all except population variables. This allows switching to be described in the region of relaxation rates typically found in current experiments. This Fokker-Planck equation has the novel property of possessing exact potential solutions, even with detunings of both the laser and interferometer. 相似文献
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Decoherence of a qubit system interacting with a bosonic reservoir is considered when there is at most one excitation in the whole system and there is an initial correlation with the reservoir. An exact time-evolution of the system is obtained and the effect of the initial correlation on the time-evolution is examined in detail. 相似文献
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The time-evolution of the trace distance between two qubit states in the presence of an initial correlation with an environment is investigated by means of the exactly solvable model of qubit and environmental system, where there is at most one excitation in the whole system, It is found that the trace distance can exceed its initial value during the time-evolution under certain conditions if the qubit is initially entangled with the environment. Furthermore the Bures distance between two qubit states is investigated. It is seen that the time-evolution of the Bures distance is quite different from that of the trace distance. 相似文献
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A population model including diffusion, chemotaxis and growth is studied. Assuming that the diffusion rate and the chemotactic rate are both very small compared with the growth rate, we derive a new equation to describe the time-evolution of the aggregating region of biological individuals and show the conditions for the existence and stability of radially symmetric equilibrium solutions of the equation, which indicate the aggregation of individuals. 相似文献
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H. Grabert P. Talkner P. Hänggi H. Thomas 《Zeitschrift für Physik B Condensed Matter》1978,29(3):273-280
We study the time-evolution of the joint and the conditional probability of macroscopic variables of a closed system from a microscopic point of view. We derive an exact generalized master equation for their time rate of change which consists of two parts, one instantaneous and local in state space, the other retarded and nonlocal in state space. It is represented by stochastic operators depending both on the initial preparation and on the initial macrodistribution, which reflects the non-Markovian character of the process. The connection with the time-evolution of the single-event probability is discussed.Work Supported by the Swiss National Science Foundation 相似文献