论文标题
偶极量子气中的超氟苏酚时相变的密度波动
Density Fluctuations across the Superfluid-Supersolid Phase Transition in a Dipolar Quantum Gas
论文作者
论文摘要
相转换具有在过渡点附近增强波动的普遍特征。在这里，我们表明密度波动揭示了偶极原子的玻色子凝结物如何自发打破其翻译对称性并进入物质的超old液状态 - 这一阶段将超丰富度与结晶顺序结合在一起。我们报告了第一个直接原位测量在超氟塞酚相变跨密度波动的现场测量。这使我们能够引入一种一般而直接的方法来提取静态结构因子，估计基本激发的频谱，并为显性波动模式形象。我们观察到静态结构因子的强烈响应，并在分散关系中推断出最小的Roton最小值。此外，我们表明特征波动对应于基本激发，例如roton模式，理论上预测在量子临界点上是主导的，而超olid态也支持超氟和水晶声子。
Phase transitions share the universal feature of enhanced fluctuations near the transition point. Here we show that density fluctuations reveal how a Bose-Einstein condensate of dipolar atoms spontaneously breaks its translation symmetry and enters the supersolid state of matter -- a phase that combines superfluidity with crystalline order. We report on the first direct in situ measurement of density fluctuations across the superfluid-supersolid phase transition. This allows us to introduce a general and straightforward way to extract the static structure factor, estimate the spectrum of elementary excitations and image the dominant fluctuation patterns. We observe a strong response in the static structure factor and infer a distinct roton minimum in the dispersion relation. Furthermore, we show that the characteristic fluctuations correspond to elementary excitations such as the roton modes, which have been theoretically predicted to be dominant at the quantum critical point, and that the supersolid state supports both superfluid as well as crystal phonons.
