The entropic squeezing of superposition of two arbitrary coherent states

In this paper the superpositions of two arbitrary coherent states ｜ψ〉 = α ｜β｜ ＋ be^iψ ｜mβe^iδ〉 are constructed by using the superposition principle of quantum mechanics. The entropic squeezing effects of the quantum states are studied. The numerical results indicate that the amplitudes, the ratio between the amplitudes of two coherent states, the phase difference between the two components and the relative phase of the two coefficients play important roles in the squeezing effects of the position entropy and momentum entropy.

Amplitude-squared squeezing of superposition of coherent states

This paper discusses the amplitude-squared squeezing for the superposition of two coherent states with their phase differences being separately π/2, 3π/2, and π1, as well as for the superposition state of two pseudoclassical states. According to the analysis, it is found that the superposition state of two coherent states with their phase differences π/2 and 3π/2, and the superposition state of two pseudoclassical states both do exhibit the amplitude-squared squeezing. Also, some specific states are found to exhibit even stronger squeezing effects when relative phase of the superposition is equal to the average photon number. Amplitude-squared squeezing is dependent on the difference in phase between two coherent states.

Generation of superpositions of coherent states for an atomic sample in cavity QED

This paper proposes a scheme for generation of superpositions of coherent states of the effective bosonic mode in a collection of atoms. In the scheme an atomic sample interacts with a slightly detuned cavity mode and a resonant strong classical field. Under ceitain conditions the atomic system evolves from a coherent state to a superposition of coherent states.

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.

Superposition of Coherent States in a Mesoscopic Josephson Junction with Dissipation

A mesoscopic Josephson junction with dissipation is considered. Usually the dissipation in the system is described as a consequence of its coupling to a reservoir. By solving the master equation we show that the state of the junction can evolve in a quantum superposition of two coherent states even when the dissipation is present.

Generation of Superpositions of Coherent Interaction States Along a Straight Line via Raman Interaction

We present an alternative scheme for preparing the superpositions of coherent states along a straight line of a cavity field using degenerate atom-cavity field Raman interaction. In the scheme, a collection of A-type three-level atoms is orderly sent through the cavity to interact with the cavity field adjusted by a microwave source connected to it, followed by state-selective measurements. In this way, we can prepare the superpositions of several coherent states along a straight line with arbitrary weighting factors for the cavity field. In the scheme, the coherence of the atom-cavity system may be maintained and the second microwave field is unnecessary, which is prior to the previous scheme.

Teleportation of Unknown Superpositions of Collective Atomic Coherent States

We propose a scheme to teleport an unknown superposition of two atomic coherent states with different phases. Our scheme is based on resonant and dispersive atom-field interaction. Our scheme provides a possibility of teleporting macroscopic superposition states of many atoms first time.

Creation of Coherent Superposition States in Multilevel Systems

A powerful approach to generate multilevel superposition state in A-type manifold of levels is proposed. In the analysis, we introduce a group of rotations to transform the coupled system to a simpler form, which involves one coupled and several decoupled, dark states in the ground state manifold. Then an arbitrary superposition state of initial and final states can be created. In particular, when the Rabi frequencies of the Stokes pulses have equal magnitudes, a superposition state （equal population of the （n - 2） superposition states） will be generated. A numerical simulation of coherence generation is given. It is shown that a small transient population in metastable state decreases as the intensity of Stokes pulses increases. Experimental implementation in Neon atom is given.

Superposition Coherent States and Their Properties

Special kinds of generalized superposition states, superposition coherent states, are studied in this paper. These states can be produced by superposing a pair of coherent states ｜ α 〉 and ｜- α 〉. Their quantum statistical properties, the fluctuations of field and squeezing have been discussed in detail. These properties are dependent on superposition phase. We also describe the squeezing regions in phase space for these states.

Generation of Superpositions of Two-Mode Coherent States for the Motion of Two Trapped Ions

We propose a method for the generation of superpositions of two-mode coherent states for the center-of-mass and relative vibrational modes of two trapped ions. In the scheme the ions are driven by a single travelling-wave laser field tuned to the carrier. Then a measurement of the internal states collapses the vibrational modes to the entangled coherent state.

Emergence of the Macroscopic Quantum Superposition State in Microtubules

Many researchers conceive communication in Microtubules (MTs), and established theoretical models to show both classical and quantum information processing. In this paper, we studied the usually neglected interactions between the electronic dipole of water molecules in microtubules and the quantized electromagnetic radiation field. We find that the emergence collective coherent radiation, and it can turn into macroscopic quantum superposition state when passing through MTs. This could have a fundamental role in the quantum information processing.

Superposition solitons in two-component Bose-Einstein condensates

We develop the Hirota bilinear method and obtain the exact one and two superposition soliton solutions for two- component Bose-Einstein condensates. The conversion of three kinds of solitons including the superposition solitons, bright-bright solitons, and dark-bright solitons is discussed. With the energy analysis, we find that the superposition soliton state is an excitation state for this system. Moreover, the collision of two superposition solitons is found to be elastic.

On Diagonal P-Representation of Superposition Field of Two Light Modes

For the superposition field a^＋1＋aA^＋2 of two light modes we introduce an appropriate diagonal P-representation which is constructed on the common eigenvectors ｜z,x 〉 of （X1 -X2） and al ＋ a2, where Xi = （ai ＋ a^＋i） /√2, [ai, a^＋i] = δij. It is remarkable that ｜z, x〉make up a new quantum mechanical representation.

基于Hamming距离和量子搜索算法的联想分类器设计

针对现有联想分类器不能存储重复样本的问题,提出一种基于Hamming距离和量子搜索算法的量子联想分类器设计方法,并给出联想分类器存储和分类的线路图.该方法需提前准备5组量子比特,分别对Hamming距离、输入样本、模式样本、类别和序号进行编码.首先,根据样本总体N,计算联想分类器所需的量子位数,再利用量子旋转门和Hadamard门将初态为|0〉的量子位旋转为恰好包含N个基态的均衡叠加态;其次,根据待存储样本的类别和值,将剩余两组初始状态为|0〉的量子位通过可控操作转换为相应的量子基态;最后,基于量子最小搜索的分类方法,计算输入样本与所有存储样本之间的Ha mming距离,再使用固定相位Grover量子搜索算法搜索这些Hamming距离的最小值,最小值对应存储样本的类别即为输入样本的类别,具体的分类结果可通过测量寄存器中的量子态得到.

基于状态空间法的平面圆弧曲梁面外动力学分析

该文通过选择广义位移和与其对偶的广义力作为状态变量,建立了平面圆弧曲梁面外动力学问题的状态方程列式,并求解了工程中常见的四种边界条件下圆弧曲梁面外自由振动的频率和模态。利用状态空间列式和辛内积的概念,建立了振动模态关于质量和旋转惯量以及关于刚度的正交关系式。基于建立的振动模态关于质量和旋转惯量的正交关系式,运用模态叠加法得到了非齐次状态方程即面外强迫振动控制方程的解析解,并具体考察了竖向移动荷载作用下圆弧曲梁的动力响应。给出了数值算例,并与已有结果进行了比较,验证了该文方法在进行圆弧曲梁面外自由振动和强迫振动分析时的准确性和可靠性。

SFEP中系统功能状态叠加的形式、条件和意义

系统功能状态在SFEP中是不断波动的,当有多个SFEP在时空中同时出现时可能出现叠加现象。为研究SFEP的功能状态叠加形式和条件,基于SFEP和量子力学思想提出了研究方法。研究了SFEP和系统功能状态的关系,SFEP量子态的叠加形式、叠加需要的因素和时间条件,最后论述了叠加的物理数学意义。将因素空间投影为二维因素平面,并与演化时间轴构成了演化空间。研究的具体实现过程在演化空间中进行。结果表明:SFEP量子态的叠加形式包括张量积形式和量子态和的形式;在演化空间中时空不同的SFEP量子态不适合叠加;SFEP量子态在演化空间中是物理叠加,需满足叠加的因素条件和时间条件。最终研究认为数学叠加是物理叠加的基础,物理叠加是数学叠加的实现。

量子态叠加的事件发生柔性逻辑统一表达式研究

为了确定原因事件导致结果事件过程中蕴含的多逻辑关系,提出以多量子态叠加为基础的事件发生柔性逻辑统一表达式。根据任意多事件间逻辑关系可简化为两事件逻辑关系的前提,研究了20种柔性逻辑关系转化为事件发生逻辑表达式的形式,选择其中16种建立了四量子态叠加的事件发生柔性逻辑统一表达式。研究这16种逻辑关系,进一步确定了8种无明显相关性的逻辑关系,最终形成了三量子态叠加的事件发生柔性逻辑统一表达式。研究表明:所建表达式能同时表达8种逻辑关系叠加状态,可得到结果事件发生概率中不同逻辑的构成形式,分析了所建表达式的特点和求解过程中可能遇到的问题,并通过实例分析说明了方法的使用过程和作用。研究成果可用于系统故障演化过程中,原因事件导致结果事件的逻辑关系统一表达及故障发生概率确定。

考虑长期作用下的弱界面钢混组合梁动力响应分析

钢混组合梁在长期荷载作用下的动力特性受到混凝土徐变的影响,为研究动力因素与混凝土徐变因素耦合作用下的部分相互作用组合梁的动力特性,本文选择适当的状态变量来建立状态空间公式,然后得到两端简支边界条件下自由振动的频率特征方程和对应的各阶模态。公式是基于节点处的受力平衡与应变兼容性的基本力学微分方程利用D'Alembert原理推导出的,在此基础上还额外加入了考虑混凝土的徐变影响的系数项。然后采用模态叠加法计算部分相互作用组合梁在均布简谐荷载、集中移动荷载作用下的非齐次方程解以及动力响应。无论荷载类型如何,该数值模型都可以成功地用于模拟任意跨连续梁的时变结构行为。最后通过给出分析结果与数值结果的比对研究和若干相关参数研究,验证了数值模型的有效性。

“叠加态”景观创新设计理念研究

近年来,随着城市建设对景观设计行业的需求不断完善,景观设计理念也在随之不断进步。文章针对传统景观设计智慧,结合最新研究方向,探讨了“叠加态”景观创新设计理念的应用,明确了景观研究重点从景观本身转向人,从传统的刻画固定的物理空间场所,转而构思景观对于行为的反应,以及人能够决定景观成为何种状态,对现代景观发展理论进行了创新探索。

非匀称载荷叠加态的组合变油箱加强筋降本优化研究

如何使组合变油箱既满足安全可靠的前提条件,又充分提高钢材等原材料的利用率,节约成本,在现如今尤为关键。基于组合变油箱在非匀称载荷条件的实际工况下,采用两种不同模式的力学叠加态计算方法,对组合变油箱加强筋的布局方式和材料用量进行了优化,在满足极限工况产品安全的条件下,最大限度地达成了降低钢材使用量这一目的。经有限元仿真分析及实物样机试制,验证了该研究的可靠性和有效性。