发表机构
Sichuan Normal University; Zhejiang Normal University（四川师范大学; 浙江师范大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究证明巨原子量子拉比环在频率比趋于无穷时具有指数级简并的超辐射相，并通过量子序-by-无序效应在有限频率比下选择特定构型，为量子模拟提供新平台。
AI 中文摘要
我们证明，当原子与腔的频率比 $\eta=\Delta/\omega$ 趋于无穷时，具有匹配巨原子耦合的 $N$ 位点量子拉比环拥有 $2^N$ 个简并的超辐射构型。每个原子耦合到相隔两个位点的两个腔，光子跳跃携带 $\pi/2$ 的相位。将接触强度与光子跳跃的比率调谐后，平均场能量可化为单位点拉比能量之和，所有动量对扇区共享一个共同的临界耦合。尽管激发谱具有色散性，简并性在二次量子涨落下依然保持。在有限 $\eta$ 下，涉及局域三次非谐性的二阶过程产生阶数为 $\omega/\eta$ 的同子格伊辛耦合，选择铁磁和反铁磁超辐射构型。这种量子序-by-无序效应没有经典对应物。保留所有自旋态的四位点计算定量支持所预测的能量系数。诱导耦合与激发隙之间的分离允许一个宽温度区间内具有宏观光子占据和位移符号之间的短程关联。
英文摘要
We show that an $N$-site quantum Rabi ring with matched giant-atom couplings has $2^N$ degenerate superradiant configurations as the atomic-to-cavity frequency ratio $η=Δ/ω$ tends to infinity. Each atom couples to two cavities two sites apart, and the photon hopping carries a phase $π/2$. Tuning the ratio of contact strengths to the photon hopping reduces the mean-field energy to a sum of single-site Rabi energies, with a common critical coupling for all momentum-pair sectors. The degeneracy survives quadratic quantum fluctuations despite a dispersive excitation spectrum. At finite $η$, second-order processes involving the local cubic anharmonicity generate a same-sublattice Ising coupling of order $ω/η$, selecting ferro- and antiferro-superradiant configurations. This quantum order-by-disorder effect has no classical counterpart. Four-site calculations retaining all spin states quantitatively support the predicted energy coefficients. The separation between the induced coupling and the excitation gap allows a broad temperature interval with macroscopic photon occupation and short-range correlations between displacement signs.
Comments13 pages, 4 figures, 4 tables. Data and code available at https://doi.org/10.5281/zenodo.23202581
