Zou Ji, Bosco Stefano, Loss Daniel
Department of Physics, University of Basel, Basel, Switzerland.
npj Quantum Inf. 2024;10(1):46. doi: 10.1038/s41534-024-00842-9. Epub 2024 Apr 30.
Correlated noise across multiple qubits poses a significant challenge for achieving scalable and fault-tolerant quantum processors. Despite recent experimental efforts to quantify this noise in various qubit architectures, a comprehensive understanding of its role in qubit dynamics remains elusive. Here, we present an analytical study of the dynamics of driven qubits under spatially correlated noise, including both Markovian and non-Markovian noise. Surprisingly, we find that by operating the qubit system at low temperatures, where correlated quantum noise plays an important role, significant long-lived entanglement between qubits can be generated. Importantly, this generation process can be controlled on-demand by turning the qubit driving on and off. On the other hand, we demonstrate that by operating the system at a higher temperature, the crosstalk between qubits induced by the correlated noise is unexpectedly suppressed. We finally reveal the impact of spatio-temporally correlated 1/ noise on the decoherence rate, and how its temporal correlations restore lost entanglement. Our findings provide critical insights into not only suppressing crosstalk between qubits caused by correlated noise but also in effectively leveraging such noise as a beneficial resource for controlled entanglement generation.
多个量子比特之间的关联噪声对实现可扩展且容错的量子处理器构成了重大挑战。尽管最近在各种量子比特架构中对这种噪声进行了量化的实验努力，但对其在量子比特动力学中的作用仍缺乏全面理解。在此，我们对受空间关联噪声作用的驱动量子比特动力学进行了分析研究，包括马尔可夫噪声和非马尔可夫噪声。令人惊讶的是，我们发现通过在低温下运行量子比特系统，此时关联量子噪声起着重要作用，可以在量子比特之间产生显著的长寿命纠缠。重要的是，这种生成过程可以通过打开和关闭量子比特驱动来按需控制。另一方面，我们证明通过在较高温度下运行系统，由关联噪声引起的量子比特之间的串扰会意外地受到抑制。我们最终揭示了时空关联噪声对退相干率的影响，以及其时间关联如何恢复丢失的纠缠。我们的发现不仅为抑制由关联噪声引起的量子比特之间的串扰提供了关键见解，还为有效利用这种噪声作为受控纠缠生成的有益资源提供了关键见解。
