Towards Measuring the Non-Local Spatial Correlation Function in Strongly-Interacting One-dimensional Strontium Bose Gases

Non-local spatial correlation functions, which measure the probability of detecting two or more particles at given separations, provide a powerful tool for studying many-body systems. Much interest has been focused on one-dimensional Bose gases, which in the strongly interacting regime display fascinating behavior like fermionization. Here we present our recent progress towards measuring the non-local correlation function g⁽²⁾ in such a many-body system. We load ultracold (~100nK) ⁸⁶Sr or ⁸⁴Sr gas into a deep 2D optical lattice to create an array of isolated 1D systems. Due to the unusually large s-wave scattering length (811a₀) for ⁸⁶Sr, a 1D ⁸⁶Sr gas is expected to reach the strongly interacting regime and fermionize with experimentally realizable parameters, while a 1D ⁸⁴Sr gas remains in the weakly interacting regime. We will measure g⁽²⁾ through photoassociation of 5snd ¹D₂ ultralong-range Rydberg molecule (ULRM) dimers with principal quantum number n ranging from 40 to 50 in ⁸⁶Sr and, for comparison, in ⁸⁴Sr samples. The excitation rate for dimers in the ground vibrational state is proportional to g⁽²⁾(R_n), where R_n (~ 0.16 – 0.25μm) is the distance from the nucleus to the outer lobe of the electron wave function [1]. Thus measurement of the dimer production rate can provide information on the spatial distribution of atoms from which they are formed.

 

[1] S. K. Kanungo, et al, Phys. Rev. A. 107, 033322 (2023)