  We propose how to form spin qubits in graphene. A crucial requirement to
achieve this goal is to find quantum dot states where the usual valley
degeneracy in bulk graphene is lifted. We show that this problem can be avoided
in quantum dots based on ribbons of graphene with semiconducting armchair
boundaries. For such a setup, we find the energies and the exact wave functions
of bound states, which are required for localized qubits. Additionally, we show
that spin qubits in graphene can not only be coupled between nearest neighbor
quantum dots via Heisenberg exchange interaction but also over long distances.
This remarkable feature is a direct consequence of the quasi-relativistic
spectrum of graphene.
