Optical spin locking of a solid-state qubit
Optical spin locking of a solid-state qubit
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DOI：
10.1038/s41534-019-0206-3
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发表时间：
2019-11-12
影响因子：
7.6
通讯作者：
Atature, M.
中科院分区：
文献类型：
--
作者：
Bodey, J. H.;Stockill, R.;Atature, M.
固态自旋量子比特的量子控制通常涉及微波领域的脉冲，借鉴了成熟的磁共振光谱学工具箱。通过光学手段驱动固态自旋提供了一种高速的替代方案，在有限的自旋相干存在的情况下，这使得它成为高保真量子控制的首选方法。要将磁共振的完全多功能性带入光域，需要对光场进行完全的相位和幅度控制。在这里，我们将可编程的微波序列压印在激光场上，并通过双光子拉曼过程在半导体量子点中进行电子自旋共振。我们证明了这种方法可以得到完全的SU(2)自旋控制，其pi-旋转保真度超过98%。然后，我们通过实现特定的多轴控制序列(称为自旋锁定)来演示其多功能性。结合我们在这项工作中报道的电子-核Hartmann-Hahn共振，该序列将使量子态从电子自旋有效地相干转移到介观核系综中。
Quantum control of solid-state spin qubits typically involves pulses in the microwave domain, drawing from the well-developed toolbox of magnetic resonance spectroscopy. Driving a solid-state spin by optical means offers a high-speed alternative, which in the presence of limited spin coherence makes it the preferred approach for high-fidelity quantum control. Bringing the full versatility of magnetic spin resonance to the optical domain requires full phase and amplitude control of the optical fields. Here, we imprint a programmable microwave sequence onto a laser field and perform electron spin resonance in a semiconductor quantum dot via a two-photon Raman process. We show that this approach yields full SU(2) spin control with over 98%pi-rotation fidelity. We then demonstrate its versatility by implementing a particular multi-axis control sequence, known as spin locking. Combined with electron-nuclear Hartmann-Hahn resonances which we also report in this work, this sequence will enable efficient coherent transfer of a quantum state from the electron spin to the mesoscopic nuclear ensemble.