Solution of the time-dependent Schrödinger equation for two-dimensional spin-1/2 Heisenberg systems

Numerical calculations on two-dimensional spin-1/2 XXZ Heisenberg models are presented. The computational technique entails solving the time-dependent Schr\"odinger equation. The time propagation of wave functions is performed employing Trotter-Suzuki product formulas. The algorithms are numerically stable and are used to study models involving {}10⁷ states. With this approach both the thermodynamic properties as well as the many-particle dynamics can be obtained. Densities of states and zero-temperature dynamic magnetic structure factors are presented. For the isotropic Heisenberg antiferromagnet thermodynamic properties are computed for lattices up to 26 sites.