Teleportation of N-qubit W State without Bell-State Measurement via Selective Resonant Interaction in Cavity QED

We present a scheme in which the N-atom W state is teleported by employing the selective interactionof a cavity field with a driven three-level atom in the A configuration and detecting a single atom in one of the groundstates.The long-lived W state is teleported from atom A to atom B when the atoms B and A are sent through acavity successively and atom A is then detected.The advantage is that the present one does not involve the Bell-statemeasurement and is robust against the atomic spontaneous emission.

Generation of entangled coherent states for two cavity modes via resonant interaction with a V-type three-level atom

This paper proposes a scheme for the generation of entangled coherent states for two cavity modes. In the scheme a V-type three-level atom is sent through a two-mode cavity filled with a coherent field. After the atom cavity interaction and detection of the atomic state the cavity modes may evolve to a superposition of two-mode coherent states. As the scheme is based on resonant atom-cavity interaction, the required interaction time is short, which is important in view of the decoherence. Moreover, additional classical pulses are unnecessary before and after the atom-cavlty interaction.

An Alternative Scheme to Generate Arbitrary Anticorrelated States of a Two-Mode Field via A-type Atom Resonant Interaction with a Two-Mode Cavity Field

<Abstract>An alternative scheme is presented to generate arbitrary anticorrelated states of a two-mode field.In the scheme,a sequence of A-type three-level atoms are orderly sent across the cavity to interact with the cavity field initially in the two-mode vacuum state.The detection of all the atoms in the ground state collapses the two-mode field to the desired state.In this way,we can prepare the anticorrelated states of a two-mode field.

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

一个计划被介绍基于在梯子类型之间的反响的相互作用产生平光子的状态有一块单个模式的地的三水平的原子。在计划，合适准备的梯子类型的一个序列三水平的原子是有序的通过一个单个模式的洞送了开始。处于扎根的状态的所有原子的察觉折叠洞到需要的状态。计划与洞基于原子的反响的相互作用，并且因此，要求的相互作用时间能极大地被弄短。鉴于 decoherence，这是重要的。

Preparation of W state in resonant bimodal cavity quantum electrodynamics

A scheme is proposed for generating entangled W states with four cavity modes. In this scheme, we send a V-type three-level atom through two identical two-mode cavities in succession. After the atom exits from the second cavity, the four cavity modes are prepared in the W state. On the other hand we can obtain three-atom W states by sending three V-type three-level atoms through a two-mode cavity in turn. The present scheme does not require conditional measurement, and it is easily generalized to preparing 2n-mode W states and n-atom W states.

Generation of various multiatom entangled graph states via resonant interactions

In this paper, a scheme for generating various multiatom entangled graph states via resonant interactions is proposed. We investigate the generation of various four-atom graph states first in the ideal case and then in the case in which the cavity decay and atomic spontaneous emission are taken into consideration in the process of interaction. More importantly, we improve the possible distortion of the graph states coming from cavity decay and atomic spontaneous emission by performing appropriate unitary transforms on atoms. The generation of multiatom entangled graph states is very important for constructing quantum one-way computer in a fault-tolerant manner. The resonant interaction time is very short, which is important in the sense of decoherence. Our scheme is easy and feasible within the reach of current experimental technology.

Generation of four-photon W state via cavity QED

This paper proposes an alternative scheme for generating four-photon W state via cavity QED. The scheme bases on the resonant interaction of a A-type three level atom with two bimodal cavities. The detection of atom collapses the cavity to the desired state. Comparing with previous schemes, the advantage of this scheme is that the interaction time can be greatly shortened since it uses the resonant interaction between atom and cavities. Moreover, the proposed scheme is more experimentally feasible than the previous ones.

Preparation of entangled simultaneous nonresonant atomic states through atom-field interaction

A scheme is proposed for generating a three-atom maximal entanglement W state. It is based on the simultaneous nonresonant interaction of atoms with a single-mode cavity field. Our scheme is insensitive to the cavity field, so the cavity field in our scheme can be initially in thermal states.

Preparation of Entangled Atomic States Through Resonant Atom-Field Interaction

一个计划被建议因为二原子的格言联盟者的产生纠缠了状态，多原子格言联盟者纠缠了 W 班的状态。计划与一个单个模式的洞基于原子的同时的反响的相互作用删除。它不要求相互作用时间的精确调整。需要完成产生的时间不与原子的数字增加。

Generation of any superposition of coherent states along a straight line via resonant atom-cavity interaction

This paper proposes a scheme for generating arbitrary superpositions of several coherent states along a straight line for a cavity mode. In the scheme, several atoms are sent through a cavity initially in a strong coherent state. The superposition of several coherent states with desired coefficients may be generated if each atom is detected in the excited state after it exits the cavity. The scheme is based on resonant atom-cavity interaction and no classical field is required during and after the atom cavity interaction. Thus, the scheme is very simple and the interaction time is very short, which is important in view of decoherence.

Preparation of Multicomponent Schroedinger Cat States Through Resonant Atom-Field Interaction

A simple method is presented for generating multicomponent Schroedinger cat states through resonant atomfield interactions. In the scheme n two-level atoms, initially in ground states, are sent through a resonant cavity filled with a strong coherent field sequentially. Then state-selective measurements are performed on the atoms. The detections of the atoms in ground states collapse the cavity field onto a superposition of 2^n coherent states. This is the first way for producing superpositions of many coherent states through resonant atom-field interaction.

Decoherence-immune generation of highly entangled states for two atoms

This paper proposes a decoherence-immune scheme for generating highly entangled states for two atoms trapped in a cavity. The scheme is based on two resonant atom-cavity interactions. Conditional upon the detection of no photon, the two atoms may exchange an excitation via the first resonant interaction, which leads to entanglement. Due to the loss of the excitation, the two atoms are in a mixed entangled state. With the help of an auxiliary ground state not coupled to the cavity mode, the state related to the excitation loss is eliminated by the detection of a photon resulting from the second resonant interaction. Thus, the fidelity of entanglement is almost not affected by the decoherence.

One-Step Generation of Multi-Qubit GHZ and W States in Superconducting Transmon Qubit System

We propose a one-step method to prepare multi-qubit GHZ and W states with transmon qubits capacitively coupled to a superconducting transmission line resonator(TLR).Compared with the scheme firstly introduced by Wang et al.[Phys.Rev.B 81(2010) 104524],our schemes have longer dephasing time and much shorter operation time because the transmon qubits we used are not only more robust to the decoherence and the unavoidable parameter variations,but also have much stronger coupling constant with TLR.Based on the favourable properties of transmons and TLR,our method is more feasible in experiment.

Higgs-Like Boson and Bound State of Gauge Bosons W+W-

The Higgs-like boson H(126) discovered in 2012 is tentatively assigned to a newly found bound state of two charged gauge bosons W+W-. Starting from the scalar strong interaction hadron theory, a first principles’ theory, a nonlinear, soliton-like differential equation dependent upon the distance between the two W bosons is derived. This equation is solved on a computer. A new, nonlinear confinement mechanism, not yet understood, binds the both bosons and gives a bound state mass EB = 155.8 GeV. This EB, derived at the quantum mechanical level, is estimated to reduce to EB = 110 GeV when quantized field effects are included via coarse approximations and replacement of the bare constants by renormalized ones. These developments lead to a revised status of the standard model.

通过原子与腔场共振相互作用制备三原子的W态(英文)

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。

利用超导量子相干装置一步制备W类纠缠态(英文)

鉴于一种新形式的W类纠缠态作为纠缠通道可以实现概率为100%的量子隐形传态和密集编码的特殊优势,提出了一个基于超导量子相干装置在单模谐振腔中制备该W类纠缠态的方案。在这个方案里,只需利用超导量子相干装置和腔场发生共振相互作用,一步便可制备W类纠缠态。在目前的腔QED技术条件下,该方案是可以实现的。

通过Raman相互作用制备三个腔场的W型纠缠相干态(英文)

通过对比分立变量量子信息过程和连续变量量子信息过程的差别,利用相干态比较容易获得的这个特点,提出一种方案制备三个腔场的W型纠缠相干态.方案基于Λ型三能级原子与单模腔场的简并Raman相互作用.三个相同的腔初始分别处于相干态,三个相同的原子初始处于W型纠缠态,通过三个原子分别与三个腔的Raman相互作用、选择适当的相互作用时间并探测作用后的三个原子,三个腔场坍缩为W型纠缠相干态.在原子与腔的相互作用过程中原子不处于高能级,可以忽略原子的自发辐射,系统的相干性能够得到较好的维持.基于当前的腔量子电动力学技术,相信方案能在实验上实现.该方案制备的三个腔场W型纠缠相干态有望在连续变量量子信息过程中有重要的应用价值.文中将方案推广到制备n(n〉3)个腔场的W型纠缠相干态.

基于原子与光场共振相互作用的W态融合

基于腔量子动力学(QED)系统,从N个原子和M个原子的W态中各取1个原子同时送入真空腔场,利用原子与腔场相互作用实现2个W态融合.当原子与腔场发生共振作用后,探测腔场.结果表明:若有1个光子,则初始的2个W态以一定概率融合为(N+M)个原子W态;若腔场中没有光子,则探测飞出2个原子,若2个原子中有1个原子处于激发态,则初始的2个W态以一定概率融合为(N+M-2)个原子W态;若2个原子均处于基态,则余下的(N-1)个原子W态和(M-1)个原子W态仍可按此方案循环融合.