  The entanglement dynamics of a laser-pumped two-level quantum dot pair is
investigated in the steady-state. The closely spaced two-level emitters,
embedded in a semiconductor substrate, interact with both the environmental
vacuum modes of the electromagnetic field reservoir as well as with the lattice
vibrational phonon thermostat. We have found that the entanglement among the
pair's components is substantially enhanced due to presence of the phonon
subsystem. The reason is phonon induced decay among the symmetrical and
antisymmetrical two-qubit collective states and, consequently, the population
of the latter one. This also means that through thermal phonon bath engineering
one can access the subradiant two-particle cooperative state.
