Quantum control of hybrid nuclear-electronic qubits
Quantum control of hybrid nuclear-electronic qubits
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DOI：
10.1038/nmat3499
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发表时间：
2013-02-01
期刊：
影响因子：
41.2
通讯作者：
Monteiro, Tania S.
中科院分区：
文献类型：
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作者：
Morley, Gavin W.;Lueders, Petra;Monteiro, Tania S.
脉冲磁共振可以分别在纳秒和微秒的时间尺度上控制电子和核自旋的量子态(1)。翻转稀释自旋所需的时间比其相干时间 (2-9) 短几个数量级，从而产生了多种使用自旋量子位 (10-13) 进行量子信息处理的方案。相反，我们研究由电子和核自旋态的近 50:50 叠加组成的“混合核电子”量子位 (14,15)。使用掺铋硅，我们在 32 ns 内演示了对这些态的量子控制，这比之前使用纯核态的实验快了几个数量级 (2,3)。高达 4 ms 的相干时间比操作时间长五个数量级，并且仅受天然存在的 Si-29 核自旋杂质的限制。我们发现我们的实验和共振位置的分析理论之间存在定量一致性，以及它们的相对强度和拉比振荡频率。这些结果使固体材料中的自旋离离子阱量子位的研究又近了一步(10)。
Pulsed magnetic resonance allows the quantum state of electronic and nuclear spins to be controlled on the timescale of nanoseconds and microseconds respectively(1). The time required to flip dilute spins is orders of magnitude shorter than their coherence times(2-9), leading to several schemes for quantum information processing with spin qubits(10-13). Instead, we investigate 'hybrid nuclear-electronic' qubits(14,15) consisting of near 50:50 superpositions of the electronic and nuclear spin states. Using bismuth-doped silicon, we demonstrate quantum control over these states in 32 ns, which is orders of magnitude faster than previous experiments using pure nuclear states(2,3). The coherence times of up to 4 ms are five orders of magnitude longer than the manipulation times, and are limited only by naturally occurring Si-29 nuclear spin impurities. We find a quantitative agreement between our experiments and an analytical theory for the resonance positions, as well as their relative intensities and Rabi oscillation frequencies. These results bring spins in a solid material a step closer to research on ion-trap qubits(10).