The ability to assemble weakly-interacting subsystems is a prerequisite for implementing quantum-information processing (QIP) and generating controlled entanglement. In recent years, molecular nanomagnets have been proposed as suitable candidates for the qubit encoding and manipulation.  In particular, antiferromagnetic Cr₇Ni rings behave as effective spin-1/2 systems at low temperature and exhibit long decoherence times. These rings can be chemically linked to each other using a supramolecular approach which allows an extensive tuning of the coupling between their spins.

"Entanglement in supramolecular spin systems of two weakly coupled antiferromagnetic rings (purple Cr7Ni)", A. Candini, G. Lorusso, F. Troiani, A. Ghirri, S. Carretta, P. Santini, G. Amoretti, C. Muryn, F. Tuna, G. Timco, E. J. L. McInnes, R. E. P. Winpenny, W. Wernsdorfer, and M. Affronte, Physical Review Letters 104, 037203 (2010)

"Spin Entanglement in supramolecular structures", F. Troiani, V. Bellini, A. Candini, G. Lorusso, and M. Affronte, Nanotechnology, 21, 274009 (2010)

"Engineering the coupling between molecular spin cluster qubits by coordination chemistry", G. A. Timco, S. Carretta, F. Troiani, F. Tuna, R. J. Pritchard, E. J. L. McInnes, A. Ghirri, A. Candini, P. Santini, G. Amoretti, M. Affronte, and R. E. P. Winpenny, Nature Nanotechnology 4, 173 (2009)

“Heterometallic Rings Made from Chromium Stick Together Easily”, G. A. Timco, E. J. L. McInnes, R. G. Pritchard, F. Tuna, and R. E. P. Winpenny, Angew. Chem. Int. Ed. 47, 9681 (2008)