Quantum Simulations with Coupled Coherent States. From vibrational dynamics to electron dynamics in strong laser field

摘要: The method of Coupled Coherent States (CCS)[1-7] is a technique for direct numerical simulation of quantum many-body problems, which avoids exponential scaling of basis set with dimensionality and therefore allows exact fully quantum treatment of systems comprised of a large number of degrees of freedom. The method is based on a solution of multidimensional Schrödinger equation in the basis of trajectory guided Monte Carlo sampled coherent states. The evolution of the wave function is simulated by running an ensemble of classical trajectories of coherent states together with a system of coupled quantum equations for the coherent states amplitudes. A new feature of our approach in comparison with similar techniques [8.9] is that it uses quantum averaged potentials for running classical trajectories. This efficiently takes into account local zero point energy and results in a number of cancellations in working …