A coherent spin-photon interface in silicon
A coherent spin-photon interface in silicon
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DOI：
10.1038/nature25769
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发表时间：
2018-03-29
期刊：
影响因子：
64.8
通讯作者：
Petta, J. R.
中科院分区：
文献类型：
--
作者：
Mi, X.;Benito, M.;Petta, J. R.
硅量子点中的电子自旋由于其长相干时间和使用半导体制造技术的系统中点数量的快速缩放而成为量子计算的有吸引力的系统。虽然已经证明了两个自旋的近邻交换耦合，但通过微波频率光子的自旋相互作用可以在基于自旋的量子处理器中实现长距离自旋-自旋耦合和任意量子比特对之间的连接（“所有对所有”连接）。实现相干自旋-光子耦合是具有挑战性的，因为单个自旋的磁偶极矩很小，这限制了磁偶极子耦合速率小于1千赫兹。在这里，我们证明了硅中的单个自旋与单个微波频率光子之间的强耦合，自旋光子耦合率超过10兆赫兹。实现相干自旋-光子相互作用的机制是基于存在磁场梯度的自旋-电荷杂化。除了自旋-光子耦合外，我们还演示了单个自旋的相干控制和色散读出。这些结果为利用微波频率光子纠缠单自旋开辟了一条直接途径。
Electron spins in silicon quantum dots are attractive systems for quantum computing owing to their long coherence times and the promise of rapid scaling of the number of dots in a system using semiconductor fabrication techniques. Although nearest-neighbour exchange coupling of two spins has been demonstrated, the interaction of spins via microwave-frequency photons could enable long-distance spin-spin coupling and connections between arbitrary pairs of qubits ('all-to-all' connectivity) in a spin-based quantum processor. Realizing coherent spin-photon coupling is challenging because of the small magnetic-dipole moment of a single spin, which limits magnetic-dipole coupling rates to less than 1 kilohertz. Here we demonstrate strong coupling between a single spin in silicon and a single microwave-frequency photon, with spin-photon coupling rates of more than 10 megahertz. The mechanism that enables the coherent spin-photon interactions is based on spin-charge hybridization in the presence of a magnetic-field gradient. In addition to spin-photon coupling, we demonstrate coherent control and dispersive readout of a single spin. These results open up a direct path to entangling single spins using microwave-frequency photons.