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arXiv quant-ph/0302109quant-ph
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相干布居转移在量子信息处理中的应用

Applications of Coherent Population Transfer to Quantum Information Processing

R. G. Beausoleil, W. J. Munro, T. P. Spiller

摘要:

我们开发了一个理论框架,探索量子力学相干布居转移现象,最终目标是构建忠实的经典和量子信息处理应用程序的设备模型。首先,我们概述了一般形式主义的弱场量子光学的薛定谔图片,我们包括一个一般的现象学表示的林德布拉德退相干机制。我们使用这种形式主义来描述一个或多个传播的经典或量子激光场的一个单一的静态多能级原子的相互作用,我们详细描述了电磁诱导透明的几种表现形式和应用。除了提供一个清晰的描述的非线性光学特性的电磁透明的系统,导致“超低光”,我们验证-在原则上-一个多粒子原子或分子系统可以用作低功率光开关或量子移相器。然而,我们证明了显着的退相效应的存在下,破坏了诱导的透明度,增加与探测场弱相互作用的粒子的数量只会进一步降低非线性。最后,一个详细的计算的相对量子相位诱导的原子系统上的空间不同的Fock态的叠加预测,一个显着的准克尔非线性和低熵不能同时实现在任意的自发发射率的存在。在我们的模型中,我们确定了这个系统作为一个量子位和两个量子位条件相位门需要满足的约束。

英文摘要:

We develop a theoretical framework for the exploration of quantum mechanical coherent population transfer phenomena, with the ultimate goal of constructing faithful models of devices for classical and quantum information processing applications. We begin by outlining a general formalism for weak-field quantum optics in the Schrödinger picture, and we include a general phenomenological representation of Lindblad decoherence mechanisms. We use this formalism to describe the interaction of a single stationary multilevel atom with one or more propagating classical or quantum laser fields, and we describe in detail several manifestations and applications of electromagnetically induced transparency. In addition to providing a clear description of the nonlinear optical characteristics of electromagnetically transparent systems that lead to ``ultraslow light,'' we verify that -- in principle -- a multi-particle atomic or molecular system could be used as either a low power optical switch or a quantum phase shifter. However, we demonstrate that the presence of significant dephasing effects destroys the induced transparency, and that increasing the number of particles weakly interacting with the probe field only reduces the nonlinearity further. Finally, a detailed calculation of the relative quantum phase induced by a system of atoms on a superposition of spatially distinct Fock states predicts that a significant quasi-Kerr nonlinearity and a low entropy cannot be simultaneously achieved in the presence of arbitrary spontaneous emission rates. Within our model, we identify the constraints that need to be met for this system to act as a one-qubit and a two-qubit conditional phase gate.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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