Quantum sensing of a coherent single spin excitation in a nuclear ensemble
Quantum sensing of a coherent single spin excitation in a nuclear ensemble
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DOI：
10.1038/s41567-020-01161-4
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发表时间：
2021-02-15
期刊：
影响因子：
19.6
通讯作者：
Atature, M.
中科院分区：
文献类型：
--
作者：
Jackson, D. M.;Gangloff, D. A.;Atature, M.
利用系综与电子自旋量子点之间的耦合，以百万分之一的精度检测了半导体核自旋系综中的单个激发。通过代理量子位访问单个量子水平上的相干相互作用对象的集合在紧急量子现象的研究中具有变革性。孤立核自旋系综由于其相干性是一个很好的平台，但是单自旋激振的精确感知仍然是一个难以实现的问题。在这里，我们实现了一个单一的核自旋激发（核磁振子）的量子传感在一个密集的集合约8万个核。对电子代理量子位的拉姆齐测量使我们能够感知由单个核磁振子引起的超精细位移。我们通过这种超精细位移的光谱依赖性来解析由原子种类和自旋极性区分的多磁振子模式。最后，我们观察到由集体拉比振荡引起的随时间的位移，揭示了系综中量子相关的积累和退相干之间的竞争。这些技术可以扩展到探测整体的工程量子态，如长寿命记忆态。
A single excitation in a semiconductor nuclear spin ensemble is detected with parts-per-million accuracy using the coupling between the ensemble and an electron-spin quantum dot.Accessing an ensemble of coherently interacting objects at the level of single quanta via a proxy qubit is transformative in the investigations of emergent quantum phenomena. An isolated nuclear spin ensemble is a remarkable platform owing to its coherence, but sensing its excitations with single spin precision has remained elusive. Here we achieve quantum sensing of a single nuclear-spin excitation (a nuclear magnon) in a dense ensemble of approximately 80,000 nuclei. A Ramsey measurement on the electron proxy qubit enables us to sense the hyperfine shift induced by a single nuclear magnon. We resolve multiple magnon modes distinguished by atomic species and spin polarity via the spectral dependence of this hyperfine shift. Finally, we observe the time-dependent shift induced by collective Rabi oscillations, revealing the competition between the buildup of quantum correlations and decoherence in the ensemble. These techniques could be extended to probe the engineered quantum states of the ensemble such as long-lived memory states.