Monte Carlo Bethe-ansatz approach for the study of the Lieb-Liniger model

We have developed a Monte Carlo algorithm to explore the equilibrium and out-of-equilibrium properties of the Lieb-Liniger model. This Monte Carlo Bethe-ansatz (MCBA) algorithm has enabled us to successfully reconstruct statistical ensembles for equilibrium or postquench dynamics, thereby facilitating the calculation of macroscopic quantities of integrable models. Our results substantiate the validity of the (quench) thermodynamic Bethe-ansatz equation from the perspective of first-principles statistical physics. Additionally, we have employed this method to study the generalized Gibbs ensemble in relation to the postquench dynamics of the Lieb-Liniger model. Furthermore, we have demonstrated the MCBA algorithm's capacity to calculate correlations using Bethe-ansatz wave functions. Our approach offers an efficient methodology for the investigation of the equilibrium and out-of-equilibrium properties of integrable systems.