Fallani L, Lye J E, Guarrera V, Fort C, Inguscio M
LENS European Laboratory for Nonlinear Spectroscopy and Dipartimento di Fisica, Università di Firenze, via Nello Carrara 1, I-50019 Sesto Fiorentino (FI), Italy.
Phys Rev Lett. 2007 Mar 30;98(13):130404. doi: 10.1103/PhysRevLett.98.130404.
We use a bichromatic optical lattice to experimentally realize a disordered system of ultracold strongly interacting 87Rb bosons. In the absence of disorder, the atoms are pinned by repulsive interactions in the sites of an ideal optical crystal, forming one-dimensional Mott-insulator states. We measure the excitation spectrum of the system as a function of disorder strength and characterize its phase-coherence properties with a time-of-flight technique. Increasing disorder, we observe a broadening of the Mott-insulator resonances and the transition to a state with vanishing long-range phase coherence and a flat density of excitations, which suggest the formation of a Bose-glass phase.
我们使用双色光学晶格通过实验实现了一个由超冷强相互作用的87Rb玻色子组成的无序系统。在没有无序的情况下，原子通过排斥相互作用被束缚在理想光学晶体的格点上，形成一维莫特绝缘态。我们测量了该系统的激发谱随无序强度的变化，并使用飞行时间技术表征其相位相干特性。随着无序程度的增加，我们观察到莫特绝缘态共振的展宽以及向长程相位相干消失且激发态密度平坦的状态的转变，这表明形成了玻色玻璃相。
