利用单模腔肠与二能级原子的共振相互作用制备纯Fock态

利用单模腔场与二能级原子的共振相互作用，通过对原子进行选择性测量，在一定条件下，制备了纯Ｆｏｃｋ态。     

利用原子-腔场共振相互作用制备多原子缠结态

提出了一个利用量子腔场与原子的共振相互作用制备多原子缠结态的方案.首先将一个初态制备在基态和激发态的叠加态的二能级原子注入一个真空态腔场中.原子通过腔时产生原子-场缠结.制备于基态的其它二能级原子分别以不同角度注入腔场,在与腔场相互作用时可制得多原子缠结态,而空腔仍然保持在真空态.与现存的方案比较,该方案在实验上更容易实现.     

利用V形三能级原子与光场Raman相互作用制备多原子GHZ态

提出了一种利用V形三能级原子与光场Raman相互作用制备多原子GHZ态的方法. 关键词： GHZ态 Raman相互作用 V形三能级原子     

制备相干态腔场GHZ态

提出了一种利用简并Ⅴ型三能级原子与相干态光场(大失谐条件下)Raman相互作用实现类自旋的腔场Greenberger-Home-Zeilinger(即GHZ)态的新方案。     

运动的二能级原子与双模量子化腔场的相互作用

研究了一个微波激射器, 其腔内是单个运动的二能级原子与一双模量子化腔场的相互作用. 用修饰态来描述系统态矢量, 分析了在热原子状态下, 双模光场配制成不同的状态, 失谐量 对微波激射器的原子辐射率的影响. 关键词： 二能级原子 双模量子化腔场 原子辐射率     

利用原子腔场的Raman相互作用制备多种形式的原子纠缠态

提出了一种利用Λ型三能级原子与相干态腔场的Raman相互作用制备原子纠缠态的方案.研究表明,在简单的条件下,可获得多种形式的原子纠缠态 关键词：     

通过原子与腔场共振相互作用制备三原子的W态

提出了一种简单、可行的三原子W态制备方案，它是基于三个二能级原子与一个单模腔场共振相互作用实现的。通过控制原子与腔场相互作用时间和耦合参数，无需对腔场态的探测，就可获得三原子的W态。此外，讨论了在现有实验技术下本方案实现的可能性。     

含二能级原子共振腔的透过率谱

本文提出了计算含二能级原子共振腔的模型,并计算透过率随入射波长的变化。结果表明三峰结构可认为是真空场Rabi振荡特征的体现。 关键词：     

原子在双腔场间的共振隧穿

考虑单个二能级原子穿过2个空间分离的单模腔场,研究原子质心运动的动能、腔长与腔间距对原子透射率的影响。结果表明：当原子的动能比较大时,原子有足够的能量穿透腔场对其的阻挡,此时只有腔长的变化对原子的透射有微小的影响而腔间距的作用则可以忽略;当原子的动能较小时,原子本身的能量小于腔场势垒的能量,此时腔长与腔间距对原子透射率的影响极为明显。     

利用∧型三能级原子与腔场的Raman相互作用制备二项式态的叠加态

提出了一种制备二项式态的叠加态,亦即类Schr6山nger猫态的方案。在这个方案里,A型三能级原子被送入初始时处于二项式态的腔中,通过原子一腔场的Raman相互作用,原子一胜场系统处于缠结态·通过对原子的选择测量,原子一腔场塌缩到类Schrodnger猫态。     

Interaction of Negative Binomial States with Two-Level Atoms

We study the interaction of negative binomial states with two-level atoms. The dynamical evolutions of atomic population inversion, field entropy, Q function, and phase distribution are investigated in detail. The field becomes a superposition of negative binomial states at certain times, and this is confirmed further by its photon number distribution.     

Properties of Superposit ion of Displaced Number States and Their Interaction with Two-Level Atoms

We obtain the compact form of matrix elements of displacement operator between number states which is convenient for numerical computations by invoking the generalized Hypergeometric functions. The nonclassical properties of superposition of displaced number states and generation of them in Kerr medium are studied in detail. The evolution of atomic population inversion in the intensity-dependent Jaynes-Cummings model with the present superposition states as its input is also investigated.     

Preparation of Two-atoms Entangled States via the Quantized Cavity Field Resonant Interaction with Atom

A scheme for preparation of the two-atoms entangled state via the resonant interaction of a quantized cavity field with atom is presented. It is injected an two-level atom initially prepared in the superposition of the ground state and excited state through the cavity prepared in the vacuum state. The atom passing through the cavity creates atom-field entanglement. The second two-level atom prepared in the ground state is injected into the cavity at different angle. After the interaction with the cavity field, the two-atoms entangled state is produced and the cavity field is still in the vacuun state. Comparing with the existing schemes, ours is easier to realize experimently.     

Preparation of Entangled Atomic States Through Resonant Atom-Field Interaction

A scheme is proposed for the generation of two-atom maximally entangled states and multi-atom maximally entangled states of W class. The scheme is based on the simultaneous resonant interaction of atoms with a single-mode cavity field. It does not require accurate adjustment of the interaction time. The time needed to complete the generation does not increase with the number of the atom.     

双光子过程耦合腔系统中的纠缠特性

研究了双光子过程原子与耦合腔相互作用系统,给出了系统总激发数等于2时态矢的演化。采用负本征值来描述两个子系统间的纠缠,利用数值计算方法研究了系统中原子与原子间、腔场与腔场间和原子与腔场间的纠缠特性。讨论了腔场间的耦合强度变化对纠缠特性的影响。研究结果表明:随着腔场间耦合的增强,两原子间的纠缠增强,但原子与腔场间和两腔场间的纠缠却减弱。     

Joint Remote Preparation of a General Three-Qubit State via Non-maximally GHZ States

In this paper, we use three non-maximally GHZ states as the quantum channel and then propose two schemes to realize joint remotely preparing the general three-qubit state. For the first scheme, we show that the joint remotely state preparation (JRSP) can be successfully realized with a certain probability by performing information splitting, introducing an ancilla and proper measurement. Moreover, for the second scheme, we establish a new method to split information which needn’t to introduce the ancilla on the receiver’s side and can achieve better security.     

Deterministic Joint Remote Preparation of a Four-Qubit Cluster-Type State via GHZ States

A scheme for the deterministic joint remote preparation of a four-qubit cluster-type state using only two Greenberger-Horne-Zeilinger (GHZ) states as quantum channels is presented. In this scheme, the first sender performs a two-qubit projective measurement according to the real coefficient of the desired state. Then, the other sender utilizes the measurement result and the complex coefficient to perform another projective measurement. To obtain the desired state, the receiver applies appropriate unitary operations to his/her own two qubits and two CNOT operations to the two ancillary ones. Most interestingly, our scheme can achieve unit success probability, i.e., P _{s u c} =1. Furthermore, comparison reveals that the efficiency is higher than that of most other analogous schemes.     

Remote Preparation of Three-Particle GHZ Class States

We propose a remote state preparation （RSP） scheme of three-particle Greenberger Horne-Zeilinger （GHZ） class states, where quantum channels are composed of two maximally entangled states. With the aid of forward classical bits, the preparation of the original state can be successfully realized with the probability 1/2, the necessary classical communication cost is 0.5 bit on average. If the state to be prepared belongs to some special states, the success probability of preparation can achieve 1 after consuming one extra bit on average. We then generalize this scheme to the case that the quantum channels consist of two non-maximally entangled states.     

Generating Even-Photon State via Resonant Interaction Between Ladder-Type Three-Level Atoms with a Single-Mode Field

A scheme is presented to generate even-photon state based on resonant interaction between ladder-type three-level atoms with a single-mode field. In the scheme, a sequence of suitably prepared ladder-type three-level atoms are orderly sent through a single-mode cavity initiaJly in vacuum state. The detection of a J1 the atoms in the ground states collapses the cavity to the desired state. The scheme is based on the resonant interaction of atoms with the cavity, and thus the required interaction time can be greatly shortened. This is important in view of decoherence.     

Thermal Entanglement Between Two Two-Level Atoms in a Two-Photon Jaynes-Cummings Model with an Added Kerr Medium

In this paper, we consider a Hamiltonian model that includes interaction of two coupled two-level atoms with a single-mode quantized electromagnetic field in a cavity via the degenerate two-photon transition. The cavity is filled with a Kerr-like medium and is held at a temperature T. The free field Hamiltonian possesses the su(1,1) symmetry which realized by either even or odd photon-number states. The total number of excitation as a constant of motion, provides a decomposition of the Hilbert space of system into direct sums of invariant subspaces. As a results, the representation of the Hamiltonian becomes block-diagonal matrix with three blocks. After diagonalizing each block, we obtain thermal state of system in the whole Hilbert space and within its excitation subspaces. Finally, the effect of temperature, atom-atom and Kerr-type couplings on the degree of thermal entanglement between the atoms are investigated. Our results show that within the single-excitation subspace spanned with odd photon-number states, the entanglement between the atoms is thermally robust.