Dinuclear Molecules of Lanthanides as Prototypes of CNOT and SWAP Quantum Gates

G. Aromí^a, D. Aguilà^a, L. A. Barrios^a, V. Velasco^a, S. J. Teat^c, F. Luis^b, O. Roubeau^b, A. Repollés^b, J. P. Alonso^b

^a Departament de Química Inorgànica, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain.

^b Instituto de Ciencia de Materiales de Aragón, CSIC and Universidad de Zaragoza, Plaza San Francisco s/n, 50009, Zaragoza, Spain.

^c Advanced Light Source, Berkeley Laboratory, 1 Cyclotron Rd, Berkeley, CA 94720, USA.

The manipulation of the quantum states of electronic spins has been proposed as a possible technology for the realization of the principles of quantum computing.[1] The spins can be confined in various forms of matter, but one that seems convenient is within metals of discrete coordination molecules,[2-4] which can then be processed or localized conveniently, prepared in any desired amount with complete reproducibility and have their properties tuned by chemical synthesis. Here we discuss the synthesis of a family of dissymmetric dinuclear coordination complexes, [Ln2], (Ln=any lanthanide, Figure, left)[5] that fulfill many of the requirements necessary to act as CNOT or SWAP quantum gates.[6] The synthetic method also allows for the controlled preparation of a large number of heterometallic analogues, [LnLn’]. This provides the possibility to study any of the two individual qubits within the complex by having it be accompanied by a diamagnetic metal at the place of the other qubit (eg, [LaLn’] or [LnY]) or to explore other implementation schemes through the preparation and study of different combinations (such as [CeEr]). The physical properties proving the suitability of these chemical systems to embody 2-qubit quantum gates will be discussed (Figure right).

[1] T. D. Ladd et al. Nature 464, 45-53 (2010).

[2] G. Aromí et al. Chem. Soc. Rev. 41, 537-546 (2012).

[3] J. Lehmann et al. Nat. Nanotechnol. 2, 312-317 (2007).

[4] G. A. Timco et al. Chem. Soc. Rev. 40, 3067-3075 (2011).

[5] D. Aguilà et al. Chem., Eur. J. 15, 11235-11243 (2009).

[6] F. Luis et al. Phys. Rev. Lett. 107, 117203 (2011).