High-accuracy Trotter-formula method for path integrals

Path integrals are a powerful method for calculating real time, finite temperature, and ground state properties of quantum systems. By exploiting some remarkable properties of the symmetric Trotter formula and the discrete Fourier transform, we arrive at a high-accuracy method for removing "time slice" errors in Trotter-approximated propagators. We provide an explicit demonstration of the method applied to the two-body density matrix of He4. Our method is simultaneously fast, high precision, and computationally simple and can be applied to a wide variety of quantum propagators.