Quantum time correlation functions from complex time Monte Carlo simulations: A maximum entropy approach

Monte Carlo simulations were combined with the maximum entropy numerical analytic continuation techniques for calculating the quantum time correlation functions. Real-time correlation functions were found to be suitable for the Monte Carlo methods as they were obtained by numerically inverting the data. Symmetrized time correlation functions were introduced to make the operation more stable. The methods were tested for one-dimensional nondissipiative systems and systems interacting in a dissipiative environment.