Laboratoire Charles Fabry, Institut d'Optique, UMR8501 du CNRS, Palaiseau, France.
Phys Rev Lett. 2011 Jun 10;106(23):230405. doi: 10.1103/PhysRevLett.106.230405.
We report on local, in situ measurements of atom number fluctuations in slices of a one-dimensional Bose gas on an atom chip setup. By using current modulation techniques to prevent cloud fragmentation, we are able to probe the crossover from weak to strong interactions. For weak interactions, fluctuations go continuously from super- to sub-Poissonian as the density is increased, which is a signature of the transition between the subregimes where the two-body correlation function is dominated, respectively, by thermal and quantum contributions. At stronger interactions, the super-Poissonian region disappears, and the fluctuations go directly from Poissonian to sub-Poissonian, as expected for a "fermionized" gas.
我们报告了在原子芯片装置上一维玻色气体切片中原子数波动的局部、原位测量结果。通过使用电流调制技术防止云碎裂，我们能够探测从弱相互作用到强相互作用的交叉。对于弱相互作用，随着密度的增加，波动从超泊松到亚泊松连续变化，这是两种状态之间的过渡特征，在这两种状态下，双体相关函数分别由热贡献和量子贡献主导。在更强的相互作用下，超泊松区域消失，波动直接从泊松到亚泊松，这与“费米化”气体的预期相符。
