Speaker
Description
Since the early days of Bose-Einstein condensation in ultracold gas experiments the momentum distribution of the atoms has been a pivotal experimental observable. Measured via time-of-flight imaging, the momentum distribution has allowed to observe and characterize a wide range of phenomena in a wide range of systems. It also contributed to the development of theories describing out-of-equilibrium behaviour in 1D gases, such as being a key quantity in testing the accuracy of generalized hydrodynamics and various other important works.
In this talk we report on our recent results on introducing a general approximate method for calculating the one-body correlations and the momentum distributions of one-dimensional Bose gases at finite interaction strengths and temperatures trapped in smooth confining potentials. Our method combines asymptotic techniques for the long-distance behavior of the gas (similar to Luttinger liquid theory) with known short-distance expansions. We derive analytical results for the limiting cases of strong and weak interactions, and provide a general procedure for calculating one-body correlations at any interaction strength using a numerical method used to compute Green’s functions (needed as input to our theory). We benchmark our method against exact numerical calculations and compare its predictions to recent experimental results, finding good agreement.
