Max-Planck-Institut für Quantenoptik, Garching, Germany.
Science. 2011 Oct 14;334(6053):200-3. doi: 10.1126/science.1209284.
Quantum phases of matter are characterized by the underlying correlations of the many-body system. Although this is typically captured by a local order parameter, it has been shown that a broad class of many-body systems possesses a hidden nonlocal order. In the case of bosonic Mott insulators, the ground state properties are governed by quantum fluctuations in the form of correlated particle-hole pairs that lead to the emergence of a nonlocal string order in one dimension. By using high-resolution imaging of low-dimensional quantum gases in an optical lattice, we directly detect these pairs with single-site and single-particle sensitivity and observe string order in the one-dimensional case.
物质的量子相的特点是多体系统的基础相关性。尽管这通常可以通过局部有序参数来描述，但已经表明，许多多体系统都具有隐藏的非局部有序性。在玻色莫特绝缘体的情况下，基态性质由相关的粒子-空穴对的量子涨落控制，这些量子涨落导致在一维中出现非局域字符串有序。通过使用光学晶格中低维量子气体的高分辨率成像，我们以单站点和单粒子的灵敏度直接探测这些对，并观察到一维情况下的字符串有序。
