Unquenching of the Polyakov-loop potential showed to be an important
improvement for the description of the phase structure and thermodynamics of
strongly-interacting matter at zero quark chemical potentials with
Polyakov-loop extended chiral models. This work constitutes the first
application of the quark backreaction on the Polyakov-loop potential at nonzero
density. The observation is that it links the chiral and deconfinement phase
transition also at small temperatures and large quark chemical potentials. The
build up of the surface tension in the Polyakov-loop extended Quark-Meson model
is explored by investigating the two and 2+1-flavour Quark-Meson model and
analysing the impact of the Polyakov-loop extension. In general, the order of
magnitude of the surface tension is given by the chiral phase transition. The
coupling of the chiral and deconfinement transition with the unquenched
Polyakov-loop potential leads to the fact that the Polyakov-loop contributes at
all temperatures.Comment: 28 pages, 13 figures; version published in Phys. Rev.
