The presence of disorder substantially influences the behaviour of physical systems. It can give rise to slow or glassy dynamics, or to a complete suppression of transport as in Anderson insulators¹, where normally extended wavefunctions such as light fields or electronic Bloch waves become exponentially localized. The combined effect of disorder and interactions is central to the richness of condensed-matter physics². In bosonic systems, it can also lead to additional quantum states such as the Bose glass^3,4—an insulating but compressible state without long-range phase coherence that emerges in disordered bosonic systems and is distinct from the well-known superfluid and Mott insulating ground states of interacting bosons. Here we report the experimental realization of the two-dimensional Bose glass using ultracold atoms in an eight-fold symmetric quasicrystalline optical lattice⁵. By probing the coherence properties of the system, we observe a Bose-glass-to-superfluid transition and map out the phase diagram in the weakly interacting regime. We furthermore demonstrate that it is not possible to adiabatically traverse the Bose glass on typical experimental timescales by examining the capability to restore coherence and discuss the connection to the expected non-ergodicity of the Bose glass. Our observations are in good agreement with recent quantum Monte Carlo predictions⁶ and pave the way for experimentally testing the connection between the Bose glass, many-body localization and glassy dynamics more generally^7,8.

无序的存在会极大地影响物理系统的行为。它可以产生缓慢或玻璃状动力学，或者像安德森绝缘体¹那样完全抑制输运，其中通常扩展的波函数（例如光场或电子布洛赫波）变得呈指数局域化。无序和相互作用的综合效应是凝聚态物理丰富性的核心² 。在玻色子系统中，它还可以导致额外的量子态，例如玻色玻璃^3,4——一种绝缘但可压缩的状态，没有长程相位相干性，出现在无序玻色子系统中，与众所周知的超流体和莫特绝缘不同相互作用的玻色子的基态。在这里，我们报告了在八重对称准晶光学晶格中使用超冷原子实验实现二维玻色玻璃⁵ 。通过探测系统的相干特性，我们观察到玻色玻璃到超流体的转变，并绘制出弱相互作用状态下的相图。我们进一步证明，通过检查恢复相干性的能力并讨论与玻色玻璃预期非遍历性的联系，在典型的实验时间尺度上绝热地穿越玻色玻璃是不可能的。我们的观察结果与最近的量子蒙特卡罗预测非常一致⁶ ，并为实验测试玻色玻璃、多体定位和更普遍的玻璃动力学之间的联系铺平了道路^7,8 。