  We search for possibly existent bound states in the heavy-light tetraquark
channels with quark content $ \bar{b}\bar{b}ud $, $ \bar{b}\bar{b}us $ and $
\bar{b}\bar{c}ud $ using lattice QCD. We carry out calculations on several
gauge link ensembles with $ N_f=2+1 $ flavours of domain-wall fermions and
consider a basis of local and non-local interpolators. Besides extracting the
energy spectrum from the correlation matrices, we also perform a L\"uscher
analysis to extrapolate our results to infinite volume.
