JILA, National Institute of Standards and Technology and University of Colorado, Boulder, CO 80309, USA.
Science. 2013 Aug 9;341(6146):632-6. doi: 10.1126/science.1236929.
Strongly interacting quantum many-body systems arise in many areas of physics, but their complexity generally precludes exact solutions to their dynamics. We explored a strongly interacting two-level system formed by the clock states in (87)Sr as a laboratory for the study of quantum many-body effects. Our collective spin measurements reveal signatures of the development of many-body correlations during the dynamical evolution. We derived a many-body Hamiltonian that describes the experimental observation of atomic spin coherence decay, density-dependent frequency shifts, severely distorted lineshapes, and correlated spin noise. These investigations open the door to further explorations of quantum many-body effects and entanglement through use of highly coherent and precisely controlled optical lattice clocks.
强相互作用的量子多体系统出现在物理学的许多领域，但它们的复杂性通常排除了对其动力学的精确求解。我们研究了由 (87)Sr 中的钟态形成的强相互作用的双能级系统，作为研究量子多体效应的实验室。我们的集体自旋测量揭示了在动力学演化过程中多体相关性发展的特征。我们推导出一个多体哈密顿量，该哈密顿量描述了原子自旋相干衰变、与密度相关的频率移动、严重变形的线谱以及相关的自旋噪声的实验观测。这些研究为通过使用高度相干和精确控制的光晶格钟进一步探索量子多体效应和纠缠打开了大门。
