Magnetic Dipolar Ordering and Quantum Phase Transition in an Fe8 Molecular Magnet

Enrique Burzuri (1) , Fernando Luìs (1) , Bernard Barbara (2) , Rafik Ballou (3) , Eric Ressouche (4) , Oscar Montero (1) , Javier Campo (1) , Satoru Maegawa (5)

1 ICMA-CSIC - Instituto de Ciencia de Materiales de Aragón [Saragoza, España]
2 NEEL - QuantECA - Circuits électroniques quantiques Alpes
3 NEEL - MagSup - Magnétisme et Supraconductivité
4 SPSMS - UMR 9001 - Service de Physique Statistique, Magnétisme et Supraconductivité
5 Graduate School of Human and Environmental Studies - Kyoto University

We show that a crystal of mesoscopic Fe8 single-molecule magnets is an experimental realization of the quantum Ising model in a transverse field, with dipolar interactions. Quantum annealing has enabled us to explore the quantum and classical phase transitions between the paramagnetic and ferromagnetic phases, at thermodynamical equilibrium. The phase diagram and critical exponents that we obtain agree with expectations for the mean-field universality class.

Domaines: Electrons fortement corrélés [cond-mat.str-el]

Enrique Burzuri, Fernando Luìs, Bernard Barbara, Rafik Ballou, Eric Ressouche, et al.. Magnetic Dipolar Ordering and Quantum Phase Transition in an Fe8 Molecular Magnet. Physical Review Letters, 2011, 107, pp.097203. ⟨10.1103/PhysRevLett.107.097203⟩. ⟨hal-00963898⟩