Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
Nat Commun. 2013;4:2254. doi: 10.1038/ncomms3254.
Realistic quantum computing is subject to noise. Therefore, an important frontier in quantum computing is to implement noise-resilient quantum control over qubits. At the same time, dynamical decoupling can protect the coherence of qubits. Here we demonstrate non-trivial quantum evolution steered by dynamical decoupling control, which simultaneously suppresses noise effects. We design and implement a self-protected controlled-NOT gate on the electron spin of a nitrogen-vacancy centre and a nearby carbon-13 nuclear spin in diamond at room temperature, by employing an engineered dynamical decoupling control on the electron spin. Final state fidelity of 0.91(1) is observed in preparation of a Bell state using the gate. At the same time, the qubit coherence time is elongated at least 30 fold. The design scheme does not require the dynamical decoupling control to commute with the qubit interaction and therefore works for general qubit systems. This work marks a step towards implementing realistic quantum computing systems.
真实的量子计算受制于噪声。因此，量子计算的一个重要前沿领域是对量子位实施抗噪量子控制。同时，动态去耦可以保护量子位的相干性。在这里，我们展示了通过动态去耦控制引导的非平凡量子演化，该控制同时抑制了噪声效应。我们通过对电子自旋进行工程化的动态去耦控制，在金刚石中的氮空位中心和附近的碳-13核自旋上设计并实现了自我保护的受控-NOT 门，室温下电子自旋的量子比特保真度为 0.91(1)。同时，量子比特相干时间延长了至少 30 倍。该设计方案不需要动态去耦控制与量子比特相互作用交换，因此适用于一般的量子比特系统。这项工作标志着朝着实现现实量子计算系统迈出了一步。
