发表机构
College of William and Mary（威廉与玛丽学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文研究多模囚禁原子系综中热占据导致的拉姆齐对比度衰减，提出弱轴分辨哈密顿理论，发现交换相互作用可恢复集体相干性，且交叉耦合遵循逆平方热标度。
AI 中文摘要
在热占据的多模囚禁系综中，即使底层动力学保持相干，依赖于模式的失谐也能强烈抑制拉姆齐对比度。我们发展了一种弱轴分辨的哈密顿理论，其中集体模式自旋经历纵向失谐和重叠依赖的交换相互作用。在没有交换的情况下，热占据模式间的失谐分布产生相干相位混合，并在多模连续谱区域导致代数衰减的拉姆齐对比度包络。在平均场层面，交换产生一个自洽的恢复场，减少相位分散并恢复集体对比度。交叉行为由集体交换尺度与热诱导失谐展宽之间的竞争决定：当后期对比度用它们的比值表示时，不同温度下的结果坍缩到共同趋势上，交叉耦合遵循预测的逆平方热标度，数值指数为2.06。弱的不可逆纯退相限制但不消除这种恢复，表明交换重新聚焦相干的不均匀相位混合，但不能逆转不可逆的相位噪声。
英文摘要
In a thermally occupied multimode trapped ensemble, mode-dependent detunings can strongly suppress Ramsey contrast even when the underlying dynamics remains coherent. We develop a weak-axis-resolved Hamiltonian theory in which collective mode spins experience longitudinal detunings and overlap-dependent exchange interactions. Without exchange, the distribution of detunings across thermally occupied modes produces coherent phase mixing and an algebraically decaying Ramsey-contrast envelope in the many-mode continuum regime. At the mean-field level, exchange generates a self-consistent restoring field that reduces phase dispersion and restores collective contrast. The crossover is governed by the competition between the collective exchange scale and the thermally induced detuning spread: when the late-time contrast is expressed in terms of their ratio, results at different temperatures collapse onto a common trend, and the crossover coupling follows the predicted inverse-square thermal scaling, with a numerical exponent of 2.06. Weak irreversible pure dephasing limits, but does not eliminate, this recovery, demonstrating that exchange refocuses coherent inhomogeneous phase mixing but cannot reverse irreversible phase noise.
