Preparing high purity initial states for nuclear magnetic resonance quantum computing
Preparing high purity initial states for nuclear magnetic resonance quantum computing
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DOI：
10.1103/physrevlett.93.040501
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发表时间：
2004-07-23
影响因子：
8.6
通讯作者：
Taylor, RJK
中科院分区：
文献类型：
--
作者：
Anwar, MS;Blazina, D;Taylor, RJK
在这里，我们展示了如何仲氢可以用来制备一个几乎纯态的双自旋系统，这是适合于实现核磁共振量子计算。使用12 ns的激光脉冲来引发涉及纯仲氢（H-2的核自旋单线态）的化学反应。该产品，在微秒的时间尺度上形成，包含一个氢衍生的双自旋系统的有效自旋态纯度为0.916。为了通过直接冷却实现可比较的结果，将需要6.4mK的难以控制的（在液态下）温度或在室温下0.45MT的不切实际的磁场。所得到的自旋态的形成纠缠度为0.822，并且不能用局部隐变量模型来描述。
Here we demonstrate how parahydrogen can be used to prepare a two-spin system in an almost pure state which is suitable for implementing nuclear magnetic resonance quantum computation. A 12 ns laser pulse is used to initiate a chemical reaction involving pure parahydrogen (the nuclear spin singlet of H-2). The product, formed on the mus time scale, contains a hydrogen-derived two-spin system with an effective spin-state purity of 0.916. To achieve a comparable result by direct cooling would require an unmanageable (in the liquid state) temperature of 6.4 mK or an impractical magnetic field of 0.45 MT at room temperature. The resulting spin state has an entanglement of formation of 0.822 and cannot be described by local hidden variable models.