Spielman I B, Phillips W D, Porto J V
Joint Quantum Institute, National Institute of Standards and Technology, and University of Maryland, Gaithersburg, MD 20899, USA.
Phys Rev Lett. 2007 Feb 23;98(8):080404. doi: 10.1103/PhysRevLett.98.080404. Epub 2007 Feb 22.
Cold atoms in periodic potentials are versatile quantum systems for implementing simple models prevalent in condensed matter theory. Here we realize the 2D Bose-Hubbard model by loading a Bose-Einstein condensate into an optical lattice, and study the resulting Mott insulator. The measured momentum distributions agree quantitatively with theory (no adjustable parameters). In these systems, the Mott insulator forms in a spatially discrete shell structure which we probe by focusing on correlations in atom shot noise. These correlations show a marked dependence on the lattice depth, consistent with the changing size of the insulating shell expected from simple arguments.
处于周期性势场中的冷原子是用于实现凝聚态物质理论中常见简单模型的通用量子系统。在此，我们通过将玻色 - 爱因斯坦凝聚体加载到光学晶格中来实现二维玻色 - 哈伯德模型，并研究由此产生的莫特绝缘体。测量得到的动量分布与理论定量相符（无可调参数）。在这些系统中，莫特绝缘体形成一个空间离散的壳层结构，我们通过关注原子散粒噪声中的关联来对其进行探测。这些关联显示出对晶格深度的显著依赖性，这与基于简单论证所预期的绝缘壳层大小变化相一致。
