  Electrostatic confinement of charge carriers in bilayer graphene provides a
unique platform for carbon-based spin, charge or exchange qubits. By exploiting
the possibility to induce a band gap with electrostatic gating, we form a
versatile and widely tunable multi-quantum dot system. We demonstrate the
formation of single, double and triple quantum dots that are free of any sign
of disorder. In bilayer graphene we have the possibility to form tunnel
barriers using different mechanisms. We can exploit the ambipolar nature of
bilayer graphene where pn-junctions form natural tunnel barriers.
Alternatively, we can use gates to form tunnel barriers, where we can vary the
tunnel coupling by more than two orders of magnitude tuning between a deeply
Coulomb blockaded system and a Fabry-P\'erot-like cavity. Demonstrating such
tunability is an important step towards graphene-based quantum computation.
