  A calculation of the interaction potential of two heavy-light mesons in
lattice QCD is used to study the existence of tetraquark bound states. The
interaction potential of the tetraquark system is calculated on the lattice
with 2+1 flavours of dynamical fermions with lattice interpolating fields
constructed using colorwave propagators. These propagators provide a new method
for constructing all-to-all spatially smeared the interpolating fields, a
technique which allows for a better overlap with the ground state wavefunction
as well as reduced statistical noise. Potentials are extracted for 24 distinct
channels, and are fit with a phenomenological non-relativistic quark model
potential, from which a determination of the existence of bound states is made
via numerical solution of the two body radial Schr\"odinger equation.
