共查询到20条相似文献,搜索用时 46 毫秒
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光场压缩态的产生及其在亚散粒噪声光学测量和量子信息中的应用 总被引:12,自引:0,他引:12
光场压缩态是一种非经典光场,它在超标准量子极限(SQL)的高精度光学测量、超低噪声光通信及量限通信等有着广泛应用前景,是物理学和信息科学交叉前沿研究课题,文章介绍了光场压缩态的产生及它在亚散粒噪声光学测量(sub-shot-noise=limit opical measurement)和量子信息中的重要应用。 相似文献
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量子力学从1925年诞生以来,经过大量的实验检验和理论发展,肯定了它的正确性。量子力学与信息技术的结合也是必然的。当今,信息科学在推动社会文明进步和提高人类生活质量方面发挥着越来越重要的作用。 相似文献
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量子相干性作为量子力学一个最显著的特征,被认为是量子信息过程中很重要的一种量子资源.单模压缩态和双模压缩态(Einstein-Podolsky-Rosen纠缠态)均具有量子相干性,在制备和传输过程中的量子相干性对于实际应用具有重要意义.利用平衡零拍探测重构量子态的协方差矩阵,本文定量分析了量子态制备过程中的不完美以及信道传输损耗对单模和双模压缩态量子相干性的影响.实验证明量子态的压缩和纠缠特性及量子相干性对损耗均是鲁棒的.特别地,压缩和纠缠特性会随着量子态制备过程中热光子数的增大而减小,直至消失,而当压缩和纠缠均已消失时,量子相干性依然存在.实验结果为压缩态、纠缠态光场的量子相干性作为量子资源在量子信息过程中的应用提供了参考. 相似文献
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传统意义的光干涉是由两束干涉光的位相差来决定。近年来量子干涉不仅与入射场的位相差,而且与入射场的振幅有关这一全新的概念被提出。本文从压缩态与相干态干涉的角度出发,给出了实现振幅控制量子干涉的两个方案。我们既可以通过光学参量放大器来放大一个相干态的方式,也可以采用压缩态与相干态在分束器上直接干涉的方式来实现。且计算的结果也表明,得到N个光子数的福克态概率随振幅的位移量大小呈周期性变化。 相似文献
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I argue that quantum mechanics is fundamentally a theory about the representation and manipulation of information, not a theory about the mechanics of nonclassical waves or particles. The notion of quantum information is to be understood as a new physical primitive---just as, following Einsteins special theory of relativity, a field is no longer regarded as the physical manifestation of vibrations in a mechanical medium, but recognized as a new physical entity in its own right. 相似文献
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We investigate distinguishability (measured by fidelity) of the initial and the final state of a qubit, which is an object of the so-called nonideal quantum measurement of the first kind. We show that the fidelity of a nonideal measurement can be greater than the fidelity of the corresponding ideal measurement. This result is somewhat counterintuitive, and can be traced back to the quantum parallelism in quantum operations, in analogy with the quantum parallelism manifested in the quantum computing theory. In particular, as the quantum parallelism in quantum computing underlies efficient quantum algorithms, the quantum parallelism in quantum information theory underlies the classically unexpected increase of fidelity. 相似文献
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Preparation of multicomponent motional coherent and squeezed coherent states of a trapped ion 总被引:1,自引:0,他引:1 下载免费PDF全文
In this paper, we present a scheme for preparation of multicomponent motional coherent and squeezed coherent states of the quantized centre of mass of an ion trapped in a one-dimensional harmonic potential and driven by two travelling-wave laser beams tuned to the nth red and blue vibrational sidebands, respectively. In addition, our scheme also provides experimental possibility for quantum state engineering. 相似文献
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The quantum discord was introduced by Ollivier,Zurek,Henderson,and Vedral as an indicator of the degree of quantumness of mixed states.In this paper,we provide a decomposition condition for quantum discord.Moreover,we show that under the condition,the quantum correlations between the quantum systems can be captured completely by the entanglement measure.Finally,we present examples of our conclusions. 相似文献
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Quantum entanglement dynamics of two Tavis-Cummings atoms interacting with the quantum light sources in a cavity is investigated. The results show the phenomenon that the concurrence disappears abruptly in a finite time, which depends on the initial atomic states and the properties of squeezed states. We find that there are two decoherence-free states in squeezed vacuum fields: one is the singlet state, and the other entangled state is the state
that combines both excited states and ground states with a relative phase being equal to the phase of the squeezed state. 相似文献