Spin triangles as optimal units for molecule-based quantum gates

We show that isosceles antiferromagnetic spin triangles constitute simple and very advantageous units for implementing quantum gates with magnetic molecules. Indeed, the spin structure of their low-energy wave functions enables switchable effective interqubit couplings even in the presence of permanent microscopic interactions. The great advantage of the proposed hardware is that no fine tuning of microscopic intermolecular interactions is required. This significantly increases the robustness with respect to disorder of both the local and global manipulation approaches.