近日，英国剑桥大学的Ulrich Schneider&Bo Song及其研究团队取得一项新进展。经过不懈努力，他们实现二维玻色玻璃在光学准晶体中的观察。相关研究成果已于2024年9月11日在国际权威学术期刊《自然》上发表。

本文报道了在八重对称准晶光学晶格中使用超冷原子实现了二维玻色玻璃的实验研究。通过探测系统的相干性质，研究人员观察到了玻色玻璃到超流的转变，并绘制了弱相互作用条件下的相图。此外，研究人员通过检查恢复相干性的能力，证明了在典型的实验时间尺度上不可能绝热地穿过玻色玻璃，并讨论了这与玻色玻璃预期的非遍历性的联系。这项观察结果与最近的量子蒙特卡罗预测高度一致，并为实验验证玻色玻璃、多体局域化以及更广泛的玻璃态动力学之间的联系奠定了基础。

据悉，无序性的存在对物理系统的行为产生重大影响。它可以导致缓慢或玻璃态动力学，或者在如安德森绝缘体中出现输运的完全抑制，其中通常扩展的波函数（如光场或电子布洛赫波）会变得呈指数级局域化。无序性和相互作用的综合效应是凝聚态物理丰富性的核心。在玻色子系统中，它还可以导致额外的量子态，如玻色玻璃态——这是一种出现在无序玻色子系统中的绝缘但可压缩的状态，没有长程相位相干性，并且与众所周知的相互作用玻色子的超流和莫特绝缘基态不同。

附：英文原文

Title: Observing the two-dimensional Bose glass in an optical quasicrystal

Author: Yu, Jr-Chiun, Bhave, Shaurya, Reeve, Lee, Song, Bo, Schneider, Ulrich

Issue&Volume: 2024-09-11

Abstract: 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 insulators, 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 physics. In bosonic systems, it can also lead to additional quantum states such as the Bose glass—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 lattice. 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.

DOI: 10.1038/s41586-024-07875-2

Source: https://www.nature.com/articles/s41586-024-07875-2