Dimensionality plays an essential role in determining the nature and properties of a physical system. This is particularly evident in quantum systems, where interactions and fluctuations are enhanced in lower dimensions, leading to various different quantum effects. Here we show that strongly interacting ultracold bosons perceive their dimensionality as either one or two, depending on whether they are probed on short or long distances, respectively. We probe this dimensional crossover using a thorough analysis of the momentum distribution to study the characteristic decay of the one-body correlation function in the two dimensionalities and track how the decay is modified during the crossover. We find a varying two-slope structure, which substantiates the main result. These observations demonstrate how quantum properties in the strongly correlated regime evolve in the dimensional crossover as a result of the interplay between dimensionality, interactions and temperature.

维度在确定物理系统的性质和属性方面起着至关重要的作用。这在量子系统中尤其明显，其中相互作用和涨落在较低维度中增强，导致各种不同的量子效应。在这里，我们表明，强相互作用的超冷玻色子将其维度感知为一维或二维，具体取决于它们是在短距离还是长距离探测。我们通过对动量分布的彻底分析来探测这种维度交叉，以研究二维中单体相关函数的特征衰减，并跟踪衰减在交叉过程中是如何修改的。我们发现了一个不同的双斜率结构，这证实了主要结果。这些观察结果表明，由于维度、相互作用和温度之间的相互作用，强相关区域中的量子特性如何在维度交叉中演化。