Dynamics and Thermodynamics of the Low-Temperature Strongly Interacting Bose Gas
Physical Review Letters, (September 2011)DOI: 10.1103/physrevlett.107.135301
Abstract
We measure the zero-temperature equation of state of a homogeneous Bose gas of 7Li atoms by analyzing the in situ density distributions of trapped samples. For increasing repulsive interactions our data show a clear departure from mean-field theory and provide a quantitative test of the many-body corrections first predicted in 1957 by Lee, Huang, and Yang Phys. Rev. 106 1135 (1957). We further probe the dynamic response of the Bose gas to a varying interaction strength and compare it to simple theoretical models. We deduce a lower bound for the value of the universal constant ξ>0.44(8) that would characterize the universal Bose gas at the unitary limit.