Local hamiltonian Monte Carlo study of the massive Schwinger model in an external background field

Using a local hamiltonian Monte Carlo approach the massive Schwinger model in an external background field is studied on the lattice. A non-vanishing quark condensate is found for zero-fermion masses. The dependence of condensate and string tension on the background field shows the expected continuum behaviour. The approach can be used to extrapolate between weak and strong coupling regions. A first-order phase transition for a non-small mass/quark charge ratio is examined for a special background field value. (orig.)