Interface tension and chiral order parameter profile with dynamical quarks

We investigate the free energy distribution across the interface of coexisting quark and hadron matter in the framework of lattice QCD. We calculate the interface tension α with the ‘‘differential method’’ for pure SU(3) gauge theory and in the presence of dynamical quarks with four flavors. Using lattices with a spatial volume $8^2$×16 we discuss the agreement between the differential and integral method in the pure gluonic case. With dynamical fermions it turns out that the interface tension is very small and we estimate an upper bound of α/${\mathit{T}}_{\mathit{c}}^3$<0.1. The chiral condensate indicates the same width of the domain wall as the Polyakov loop distribution and the other thermodynamical observables under consideration.