AI 中文总结
研究利用3×3交叉约瑟夫森阵列非平面量子比特产生通量可调Z₃组合规范对称性，经神经网络训练预测其激发光谱，还通过超导腔诱导对称性破缺，开启用电路量子电动力学探索晶格规范理论的计划，拓展了相关实验和理论探索空间。
AI 中文摘要
电路量子电动力学将约瑟夫森结量子比特嵌入超导腔中，已成为量子计算和量子模拟的主要方法。尽管已探索了多种电路几何排列，但约瑟夫森连接性迄今都是平面的，使其有效维度较低。本文展示了一个非平面量子比特——一个3×3交叉约瑟夫森阵列——产生了通量可调的Z₃组合规范对称性（CGS），联网成晶格时可能实现自旋液体行为。观测到的激发光谱与经训练生成变分量子态的神经网络预测高度吻合。CGS点附近的精细结构分裂与因实验缺陷导致的弱隧穿或对称性破缺兼容。还利用超导腔外部诱导对称性破缺，在基态仅相差一个Z₃相位的CGS点观测到对称性恢复。这项工作开启了用电路量子电动力学工具箱探索晶格规范理论的通用计划。更广泛地说，引入非平面约瑟夫森连接性为几乎任何可想象维度和几何结构的实验和理论探索开辟了广阔空间。
英文摘要
Circuit quantum electrodynamics embeds Josephson junction qubits within superconducting cavities, and has emerged as a leading approach to quantum computing and quantum simulation. Despite the many permutations of circuit geometry that have been explored, Josephson connectivities have so far been planar, making them effectively low-dimensional. Here we show that a non-planar qubit -- a $3\times3$ crossbar Josephson array -- gives rise to flux-tunable $\mathbb{Z}_3$ combinatorial gauge symmetry (CGS), potentially enabling spin-liquid behavior when networked into a lattice. The observed excitation spectrum shows excellent agreement with predictions from a neural network trained to generate variational quantum states, demonstrating that we have predictive power over our high-dimensional quantum system. Fine-structure splittings near the CGS point are compatible with weak tunneling or symmetry breaking due to experimental imperfections. We additionally use the superconducting cavity to externally induce symmetry breaking, observing a restoration of symmetry at the CGS point where ground states differ only by a $\mathbb{Z}_3$ phase. This work initiates a general program exploring lattice gauge theories using the toolbox of circuit quantum electrodynamics. More broadly, introducing non-planar Josephson connectivities opens a vast space for experimental and theoretical exploration of structures in almost any imaginable dimensionality and geometry.
Comments7+14 pages, 5+7 figures
