论文标题
通量量子的退火路径校正
Anneal-path correction in flux qubits
论文作者
论文摘要
量子退火器需要准确的控制和优化的操作方案来降低噪声水平，以最终证明比经典算法具有计算优势。我们使用分散测量值来提取系统参数并建模设备，研究高相干性四个接一个电容分流量乘以（CSFQ）。在退火时，设备固有的Josephson交界处不对称会导致有害的非线性串扰。我们实施了一条非线性退火路径来纠正原位不对称性，从而导致量子的概率大幅增加，而量子的概率在正确的状态下，给定施加的磁通偏置。我们还通过通过较小的光谱间隙和观察能级交叉的量子特征将CSFQ电路模型的多层次结构确认。我们的结果表明，设计和实施的退火路径校正方案旨在提高高碳和高控制量子退火器的控制精度，从而提高了退火协议中成功概率的提高。
Quantum annealers require accurate control and optimized operation schemes to reduce noise levels, in order to eventually demonstrate a computational advantage over classical algorithms. We study a high coherence four-junction capacitively shunted flux qubit (CSFQ), using dispersive measurements to extract system parameters and model the device. Josephson junction asymmetry inherent to the device causes a deleterious nonlinear cross-talk when annealing the qubit. We implement a nonlinear annealing path to correct the asymmetry in-situ, resulting in a substantial increase in the probability of the qubit being in the correct state given an applied flux bias. We also confirm the multi-level structure of our CSFQ circuit model by annealing it through small spectral gaps and observing quantum signatures of energy level crossings. Our results demonstrate an anneal-path correction scheme designed and implemented to improve control accuracy for high-coherence and high-control quantum annealers, which leads to an enhancement of success probability in annealing protocols.
