基于腔QED制备W纠缠态

利用一个三能级原子与四个腔场之间相互作用研究双光子四粒子体系W态的制备,通过合适选择原子与腔场之间的相互作用时间可以获得该态的最大保真度以及成功几率     

利用超导量子相干装置制备纠缠态的方案(英文)

本文提出用两个超导量子相干装置在一个单模大失谐腔中制备一个最大纠缠态的新方案,在这个方案里,腔场态处于虚激发,在超导量子相干装置和腔场之间没有信息传递,因此对腔的品质要求大大减低.     

基于两原子同时和腔场共振作用制备两原子纠缠态的腔QED方案(英文)

我们提出了一个将两个远离的原子制备成纠缠态的腔QED方案,该方案基于两个原子同时和一个腔场发生共振作用.在这个方案里,我们利用一个事先制备好的纠缠态将另外两个分离的原子制备成纠缠态.该方案仅包含两个原子和腔场的共振相互作用,不需要用腔场存储量子信息,并且原子和腔场作用时间极短.因此,我们的方案基于目前的腔QED技术是可以实现的.     

基于腔QED技术的原子态纠缠纯化方案

基于两能级原子与单模腔场之间的失谐相互作用,我们提出了一个有效的且能够纯化任意未知原子纠缠态的纠缠纯化方案。将量子逻辑门(Phys.Rev.Lett.74,4087(1995))和纠缠纯化(Phys.Rev.Lett.76,722(1996))的理论研究的最新进展相结合提出了一个在实验上可行的纠缠纯化物理方案。     

基于腔QED的原子纠缠态的辅助克隆

本文提出一种克隆未知两原子纠缠态的方案，这种克隆方案基于腔QED技术，且在原子态制备态（Victor）的帮助下而完成。方案包括了两个步骤：第一步需要用通常的隐形传态方法，运用腔QED技术及纠缠交换实现原子纠缠态从发送者（Alice）到接收者（Bob）的隐形传送；第二步是由Victor完成来之于Alice的两原子态的离散测量，根据Victor的测量信息，Alice能够获得未知初始原子纠缠态的拷贝。     

利用原子-腔场的Raman相互作用制备类自旋多腔场纠缠态

提出了一种利用Λ型三能级原子与相干态腔场的Raman相互作用制备类自旋多腔场纠缠态的方案.     

腔QED制备三原子W态的一般方案

本文提出了一个基于腔QED技术的制备三原子最大W态的一般方案.通过讨论表明三个原子不论是被同时注入腔中还是在不同的时刻被注入腔中我们都能得到三原子最大W态.该方案可以在当前的技术范围内实现并且可以推广到制备n个原子的W态.     

与腔场耦合的两个量子点中激子的纠缠动力学

利用共生纠缠度研究了单模腔场内两个耦合量子点中激子的纠缠动力学行为.结果表明:无论腔场初始制备于奇相干态还是偶相干态,两个量子点间直接耦合作用均能减弱激子的纠缠度.在腔场初始为奇相干态时,激子的纠缠度随场模强度的增加而减小;偶相干态时,激子的纠缠度呈现一个转折变化.此外,也研究了单模腔场内平均光子数与激子准最大相干纠缠态的关联.     

增光子二模纠缠相干态的纠缠特性及其通过腔量子电动力学的制备

分析了增光子二模纠缠相干态的纠缠特性,得到共生纠缠度的解析表示式.结果表明:增光子二模纠缠相干态的共生纠缠度与叠加态的相位有非常灵敏的关系.提出了一种制备增光子相干态和增光子二模纠缠相干态的方法,其制备过程为首先把增光子相干态转化为相干态与真空态一种特殊的叠加态(叠加系数与相干态振幅有关),再通过位于高Q腔内的原子与经典激光场的相互作用,从而实现增光子相干态的制备.通过一个飞行原子先后与两个光腔中光场相互作用可以实现增光子二模纠缠相干态的制备.     

相干耦合腔场中量子纠缠信息交换传递机理研究

提出了相干多模腔场-相干耦合原子相互作用系统的物理模型.利用全量子理论,研究了该系统中多光子相互作用过程的演化性质,结果表明：在多模腔场与相干耦合多原子相互作用过程中,多光子纠缠态与多原子纠缠态可以周期性的相互转换,在此过程中,同时可以实现纠缠信息的交换传递.通过对原子保真度的数值计算,给出了纠缠信息交换传递的图示说明.并进一步揭示出纠缠信息交换传递的一般特征.目前所报道的研究结果仅是本文所得普遍性结果在各种不同情况下的特例.     

Scheme for Implementation of Quantum Game in Cavity QED

We propose an experimentally feasible scheme to implement two-player quantum game in cavity quantum electrodynamics （QED）. During the process, the cavity is only virtually excited, thus our scheme is insensitive to the cavity field states and cavity decay. The scheme can be realized in the range of current cavity QED techniques.     

Conditional Generation of Multiparticle Entanglement via Cavity QED

We propose a simple scheme to not only generate GHZ states and W states of the multiparticle but also form a new category of multiparticle entangled states by letting the A-type three-level atoms simultaneously interacting with a coherent cavity field followed by the selective measurements on the cavity mode. We investigate the influence of the cavity dissipation on the generated entangled state and discuss the experimental feasibility of our scheme. It is shown that the intensity of the coherent cavity field plays an instructive role in contribution to state preparation process while the cavity decay and the detuning between the atoms and cavity mode result in the deterioration of the generated entangled state.     

Quantum Decoherence of Charge Qubit Coupled to Nonlinear Nanomechanical Resonator

When the nonlinearity of nanomechanical resonator is not negligible,the quantum decoherence of charge qubit is studied analytically.Using nonlinear Jaynes–Cummings model,one explores the possibility of being quantum data bus for nonlinear nanomechanical resonator,the nonlinearity destroys the dynamical quantum information-storage and maintains the revival of quantum coherence of charge qubit.With the calculation of decoherence factor,we demonstrate the influence of the nonlinearity of nanomechanical resonator on engineered decoherence of charge qubit.     

Scheme for Quantum Entanglement Swapping on Cavity QED System

We propose a scheme for realizing quantum entanglement swapping between the atoms in cavity QED. With only virtual excitation of the cavity during the interaction between the atoms and cavity, the scheme is insensitive to the cavity mode states and the cavity decay. The ideas can also be utilized for realizing entanglement swapping between the atomic levels in a single atom and the atomic levels in the Bell states and between the atomic levels in the Bell states and the atomic levels in the W states.     

Conditional Generation of Multiparticle Entanglement via Cavity QED

We propose a simple scheme to not only generate GHZ states and W states of the multiparticle but also form a new category of multiparticle entangled states by letting the λ-type three-level atoms simultaneously interacting with a coherent cavity field followed by the selective measurements on the cavity mode. We investigate the influence of the cavity dissipation on the generated entangled state and discuss the experimental feasibility of our scheme. It is shown that the intensity of the coherent cavity field plays an instructive role in contribution to state preparation process while the cavity decay and the detuning between the atoms and cavity mode result in the deterioration of the generated entangled state.     

Quantum Decoherence of Charge Qubit Coupled to Nonlinear Nanomechanical Resonator

When the nonlinearity of nanomechanical resonator is not negligible, the quantum decoherence of charge qubit is studied analytically. Using nonlinear Jaynes-Cummings model, one explores the possibility of being quantum data bus for nonlinear nanomechanical resonator, the nonlinearity destroys the dynamical quantum information-storage and maintains the revival of quantum coherence of charge qubit. With the calculation of decoherence factor, we demonstrate the influence of the nonlinearity of nanomechanical resonator on engineered decoherence of charge qubit.     

Scheme for Preparation of Macroscopic Multi-component Entanglement in Cavity QED

We propose a scheme of generating multi-component entangled coherent states of cavity fields. In this scheme, the atoms pass through cavities one by one, simultaneously driven by a strong classical field in each cavity. Then the detection of the atomic states collapses the cavity fields onto multi-component entangled coherent states. It is shown that, with a judicious choice of the parameters of the classical field, we can conditionally produce macroscopic multi-dimensional maximal entanglement for the cavity modes.     

A Position-Dependent Two-Atom Entanglement in Real-Time Cavity QED System

We study a special two-atom entanglement case in assumed cavity QED experiment in which only one atom effectively exchanges a single photon with a cavity mode. We compute two-atom entanglement under position-dependent atomic resonant dipole-dipole interaction （RDDI） for large interatomic separation limit. We show that the RDDI, even t, hat which is much smaller than the maximal atomic Rabi frequency, can induce distinct diatom entanglement. The peak entanglement reaches a maximum when RDDI strength can compare with the Rabi frequency of an atom.     

Selective Atom-Cavity Interaction Scheme for Quantum Controlled-NOT Gate Using Four-Level Atoms in Cavity QED System

We propose a scheme for realization a quantum Controlled-NOT gate operation using two four-level atoms through a selective atom cavity interaction in cavity quantum electrodynamics system. In our protocol, the quantum information is encoded on the stable ground states of the two atoms. During the interaction between atoms and single-mode vacuum cavity-field, the atomic spontaneous emission is negligible as the large atom-cavity detuning effectively suppresses the spontaneous decay of the atoms. The influences of the dissipation and the deviation of interaction time on fidelity and corresponding success probability of the quantum Controlled-NOT gate and the experimental feasibility of our proposal are also discussed.     

Quantum Information Processing in a Coupled Cavity Array

We consider a one-dimensional array of L identical coupled cavities, and each cavity is doped with a two-level qubit. Experimentally, it has been developed in several varieties by the newest technology. We find that the one-qubit quantum state can be perfectly transferred through the cavity array, and the entanglement between the first two qubits can also be transferred to the last two qubits. In addition, we successfully realized the entangling gate and swap gate in the coupled cavity array.