含克尔介质微波激射器的原子辐射率

建立了含克尔介质微波激射器(micromaser with Kerr medium)的基本量子原理,分析计算了处于不同方式(热原子和超冷原子状态)下的二能级原子沿z轴穿过处于相干态的含克尔介质微腔的原子辐射率,并着重讨论了克尔介质与单模辐射场作用的耦合强度χ、失谐量Δ和原子注入速率r对原子辐射概率的影响. 关键词： 含克尔介质微波激射器 热原子和超冷原子 原子辐射率     

非等同双原子与双模腔场相互作用模型中原子布居的时间演化

研究了两个非等同二能级原子与双模腔场耦合系统中原子能级布居的时间演化规律. 并详细讨论了两个原子与双模腔场的相对耦合常数(R=g₁/g₂)和腔场的初态对原子能级布居数反转的影响. 关键词： 双模腔场 双原子体系 原子布居     

非等同两个原子与双模腔场相互作用模型中双原子偶极振幅平方压缩

本文研究了具有不同耦合系数的两个二能级原子与双模腔场相互作用系统中原子偶极振幅平方压缩随时间的演化规律.并讨论了两个原子与双模腔场的相对耦合常数(R=g1/g2)和腔场的初态对原子偶极振幅平方压缩的影响.     

微波激射器注入原子的反转特性

建立了含克尔介质微波激射器腔场稳态光子数分布的表达式.研究了在热原子、临界和超 冷原子的方式下微波激射器中原子在稳态时的反转特性. 结果表明：注入的二能级原子在不 同方式下，原子的反转特性不一样. 在热原子方式下，原子在一部分腔长L的区域无反转， 且随原子注入速率的增大，反转区域和反转概率增大. 在临界方式下，原子的反转呈现周期 性的坍塌和复苏现象. 而在冷原子方式下，原子在腔长L的全部区域无反转. 克尔效应和失 谐量使原子的反转概率减小. 关键词： 微波激射器 原子反转 光子统计 克尔效应     

原子在双腔场间的光子辐射

考虑单个二能级原子穿过两个空间分离的单模腔场,研究原子质心运动的动能、腔长和腔间距对原子的光子辐射率的影响.结果表明,在原子的动能较小时,光子辐射率在双腔系统中出现多共振峰结构并且这种共振峰的数目随腔间距的增大而增加,此时原子在第一个腔中的光子辐射率普遍大于在第二个腔中的;在原子的动能较大时,原子在第一个腔中的光子辐射率与第二个腔中的光子辐射率呈交替变化.该结果说明,可以通过控制原子的速度而对原子的光子辐射率进行调控. 关键词： 光子辐射率 单模腔场 二能级原子     

二能级原子与双模场喇曼相互作用模型的腔场谱

研究了在高Q腔内二能级原子与双模量子化光场发生双光子共振喇曼相互作用过程的腔场谱.发现原子初态的不同不改变腔场谱结构的基本特征.两模光场初态均为光子数态或均为相干态时,每模腔场谱一般都为双线结构,两条谱线的频差与另一模初始场强大致成正比,改变一模初始场可以调节另一模谱线频率.     

二能级原子与双模场喇曼相互作用模型的腔场谱

研究了在高Q腔内二能级原子与双模量子化光场发生双光子共振喇曼相互作用过程的腔场谱.发现原子初态的不同不改变腔场谱结构的基本特征.两模光场初态均为光子数态或均为相干态时,每模腔场谱一般都为双线结构,两条谱线的频差与另一模初始场强大致成正比,改变一模初始场可以调节另一模谱线频率     

Kerr效应对原子与双模场Raman相互作用模型腔场谱的影响

研究了含Kerr介质高Q腔中单个二能级原子与双模量子化光场发生Raman耦合过程的腔场谱,给出原子初态处于基态而初始光场为数态时的数值结果.发现在一般情况下,两模腔场谱均为双峰结构.Kerr效应对真空场谱结构无影响.在弱场条件下,Kerr效应的增强会导致各模高频峰明显增高,而低频峰明显降低;在强场条件下,各峰峰位都随着Kerr效应增强明显右移,谱结构整体偏离原共振频率.     

Kerr效应对原子与双模场Raman相互作用模型腔场谱的影响

研究了含Kerr介质高Q腔中单个二能级原子与双模量子化光场发生Raman耦合过程的腔场谱,给出原子初态处于基态而初始光场为数态时的数值结果.发现在一般情况下,两模腔场谱均为双峰结构.Kerr效应对真空场谱结构无影响.在弱场条件下,Kerr效应的增强会导致各模高频峰明显增高,而低频峰明显降低;在强场条件下,各峰峰位都随着Kerr效应增强明显右移,谱结构整体偏离原共振频率.     

利用双模腔场与V型三能级原子共振作用隐形传送未知原子态

给出了双模腔场与V型三能级原子共振相互作用下系统态矢的演化公式.利用V型三能级原子与双模腔场的相互作用,通过控制原子与光场的相互作用时间,并对待传送的原子态进行选择性探测,从而实现未知双原子纠缠态的隐形传送.该方案不需要进行Bell基测量,其成功几率为1/16.     

Berry phase in a generalized nonlinear two-level system

In this paper, we investigate the behaviour of the geometric phase of a more generalized nonlinear system composed of an effective two-level system interacting with a single-mode quantized cavity field. Both the field nonlinearity and the atom-field coupling nonlinearity are considered. We find that the geometric phase depends on whether the index k is an odd number or an even number in the resonant case. In addition, we also find that the geometric phase may be easily observed when the field nonlinearity is not considered. The fractional statistical phenomenon appears in this system if the strong nonlinear atom-field coupling is considered. We have also investigated the geometric phase of an effective two-level system interacting with a two-mode quantized cavity field.     

Berry phase in a generalized nonlinear two-level system

In this paper, we investigate the behaviour of the geometric phase of a more generalized nonlinear system composed of an effective two-level system interacting with a single-mode quantized cavity field. Both the field nonlinearity and the atom--field coupling nonlinearity are considered. We find that the geometric phase depends on whether the index $k$ is an odd number or an even number in the resonant case. In addition, we also find that the geometric phase may be easily observed when the field nonlinearity is not considered. The fractional statistical phenomenon appears in this system if the strong nonlinear atom--field coupling is considered. We have also investigated the geometric phase of an effective two-level system interacting with a two-mode quantized cavity field.     

All-quantized Jaynes-Cummings interaction for a trapped ultracold ion

We propose an all-quantized Jaynes-Cummings (JC) interaction between a trapped ultracold ion with a quantized radiation field. The carrier excitation gives the usual JC model in cavity QED, but the red and blue excitations will result in three-body interactions analogous to a two-mode problem in quantum optics.     

Interaction of pair coherent state with a three-level Λ-type atom and generation of a modified Bessel-Gaussian state with a vortex structure

The evolution of a system state is derived based on the nonresonant interaction of a three-level "Λ" type atom with two cavity modes at a pair coherent state and two classic fields, and a cavity field state is analysed in detail under conditional detecting. It is found that the quantized modified Bessel-Gaussian states as well as the superposition states consisting of the quantized vortex states with different weighted coefficients may be prepared through carefully preparing an initial atomic state and appropriately adjusting the interaction time. The scheme provides an additional choice to realize the two-mode quantized vortex state within the context of cavity quantum electrodynamics (QED).     

Continuous-variable Entanglement in a Correlated Spontaneous Emission Laser

We discuss the generation and evolution of entangled light in a correlated spontaneous emission laser in the linear regime. The master equation for the two-mode cavity field is derived and solved analytically in phase space. The time-dependent characteristic function in the Wigner representation for the two-mode field is obtained. It shows that the two-mode field in the cavity evolves in a two-mode Gaussian state. The entanglement degree of the two- mode field in the cavity increases initially, then decreases, and finally vanishes as the field evolves from an initial vacuum. The period of the entanglement is extended as the intensity of the driving field is increased. It is found that the entanglement still exists even when the two-mode squeezing disappears. During the entanglement period, the intensity of the field is amplified. The entanglement for the initial field being a two-mode squeezed vacuum and the entanglement of the output field are also discussed.     

利用置于光腔中的非线性耦合器制备压缩和连续变量纠缠光

利用置于光腔中的非线性耦合器制备了压缩和连续变量纠缠光.通过特征函数方法解析求解了双模腔场满足的主方程.分析发现：在一定的条件下,此系统能产生稳定的双模压缩和连续变量纠缠光,且压缩和纠缠的强度与系统的耦合参量及腔场损耗系数密切相关.     

Coherent Population Trapping in a Λ-Configuration Photoionization System in the Presence of an Autoionizing State

We investigate the atomic coherent population trapping in the system of two-mode quantized field interacting with a A-configuration atom with two lower bound states, one autoionizing state and a flat atomic continuum. The states of the field which traps the atom in its two lower bound states are given and the influence of the field induced continuum structure is examined.     

双模量子光场驱动的拉曼型光致离化系统中原子的相干俘获

研究了由双模量子光场驱动的拉曼型光致离化系统中原子的相干俘获性质，分析了反映原子－光场耦合性质的参量对系统相干俘获的影响，论证了在定的条件下，双模ＳＵ（２）相干光场可以将原子完全俘获。     

Quantum Nondemolition Measurement of Photon-Number Distribution for a Two-Mode Field

We propose a quantum nondemolition measurement of the photon-number distribution for a two-mode cavity field. In the scheme two sequences of two-level atoms interact dispersively with the respective cavity modes and resonantly with two classical fields, and then are detected continually. The field finally reduces to a two-mode Fock state. The probability of collapsing to a given Fock state is determined by the initial photon-number distribution. The scheme can be easily generalized to a field with N modes.     

Engineering Two-Mode Squeezed Vacuum Motional State of a Single Intracavity Trapped Ion

We propose to generate two-mode squeezed vacuum motional state of an intracavity trapped ion by taking the advantage of the dissipation of the cavity mode. At the first step, the steady and pure two-mode motional entanglement between two motional degrees of the cold ion is obtained by engineering the couplings of both the motional modes of the ion to the cavity field. Based on the first step, a two-mode squeezed vacuum motional state is then generated by manipulating the phases of the external laser pulses incident on the ion.