  A spatially modulated Dirac gap in a graphene sheet leads to charge
confinement, thus enabling a graphene quantum dot to be formed without the
application of external electric and magnetic fields [Appl. Phys. Lett.
\textbf{97}, 243106 (2010)]. This can be achieved provided the Dirac gap has a
local minimum in which the states become localised. In this work, the physics
of such a gap-induced dot is investigated in the continuum limit by solving the
Dirac equation. It is shown that gap-induced confined states couple to the
states introduced by an electrostatic quantum well potential. Hence the region
in which the resulting hybridized states are localised can be tuned with the
potential strength, an effect which involves Klein tunneling. The proposed
quantum dot may be used to probe quasi-relativistic effects in graphene, while
the induced confined states may be useful for graphene-based nanostructures.
