Preserving electron spin coherence in solids by optimal dynamical decoupling
Preserving electron spin coherence in solids by optimal dynamical decoupling
复制标题
通过最佳动态解耦保持固体中的电子自旋相干性
DOI：
10.1038/nature08470
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发表时间：
2009-10-29
期刊：
影响因子：
64.8
通讯作者：
Liu, R. B.
中科院分区：
文献类型：
--
作者：
Du, Jiangfeng;Rong, Xing;Liu, R. B.
为了在诸如量子计算的未来技术中利用固体中电子自旋的量子相干性，首先必须克服由于它们与噪声环境的耦合而引起的自旋退相干问题。动态去耦，它使用频闪自旋翻转，以提供一个平均耦合的环境，实际上是零，是一个特别有前途的战略，为打击退相干，因为它可以自然地集成与其他所需的功能，如量子门。在每个自旋翻转中不可避免地引入误差，因此期望最小化用于实现具有给定精度水平的动态解耦的控制脉冲的数量。这种最佳动态解耦序列最近已被探索，。然而，固态系统中最佳动态解耦的实验实现仍然是难以捉摸的。在这里，我们使用脉冲电子顺磁共振证明实验最佳的动态去耦保持电子自旋相干辐照丙二酸晶体中的温度从50 K到室温。采用七脉冲最佳动力学退耦序列，使自旋相干时间延长到30 μs左右，而在无控制时约为0.04 μs，单脉冲控制时约为6.2 μs。通过实验与微观理论的比较，我们确定了固体中相关的电子自旋退相干机制。最佳动力学解耦可以应用于其他固态系统，如具有氮空位中心的金刚石，因此奠定了室温下固体自旋的量子相干控制的基础。
To exploit the quantum coherence of electron spins in solids in future technologies such as quantum computing,, it is first vital to overcome the problem of spin decoherence due to their coupling to the noisy environment. Dynamical decoupling,,,,,,, which uses stroboscopic spin flips to give an average coupling to the environment that is effectively zero, is a particularly promising strategy for combating decoherence because it can be naturally integrated with other desired functionalities, such as quantum gates. Errors are inevitably introduced in each spin flip, so it is desirable to minimize the number of control pulses used to realize dynamical decoupling having a given level of precision. Such optimal dynamical decoupling sequences have recently been explored,,,. The experimental realization of optimal dynamical decoupling in solid-state systems, however, remains elusive. Here we use pulsed electron paramagnetic resonance to demonstrate experimentally optimal dynamical decoupling for preserving electron spin coherence in irradiated malonic acid crystals at temperatures from 50 K to room temperature. Using a seven-pulse optimal dynamical decoupling sequence, we prolonged the spin coherence time to about 30 μs; it would otherwise be about 0.04 μs without control or 6.2 μs under one-pulse control. By comparing experiments with microscopic theories, we have identified the relevant electron spin decoherence mechanisms in the solid. Optimal dynamical decoupling may be applied to other solid-state systems, such as diamonds with nitrogen-vacancy centres,,, and so lay the foundation for quantum coherence control of spins in solids at room temperature.