Formation of collective spins in frustrated clusters

Julien Robert , Virginie Simonet (1) , Benjamin Canals (2) , Rafik Ballou (1) , Elsa Lhotel (1) , Céline Darie (3) , Pierre Bordet (3) , Bachir Ouladdiaf (4) , Marc Johnson (4) , Jacques Ollivier (4) , Daniel Braithwaite (5) , Harison Rakoto (6) , Sophie de Brion (1, 7)

1 NEEL - MagSup - Magnétisme et Supraconductivité
2 NEEL - TMC - Théorie de la Matière Condensée
3 NEEL - MRS - Matériaux, Rayonnements, Structure
4 ILL - Institut Laue-Langevin
5 IMAPEC - Instrumentation, Material and Correlated Electrons Physics
6 LNCMP - Laboratoire National des Champs Magnétiques Pulsés
7 LNCMI-G - Laboratoire national des champs magnétiques intenses - Grenoble

Using magnetization, specific heat and neutron scattering measurements, as well as exact calculations on realistic models, the magnetic properties of the \lacuvo compound are characterized on a wide temperature range. At high temperature, this oxide is well described by strongly correlated atomic $S$=1/2 spins while decreasing the temperature it switches to a set of weakly interacting and randomly distributed entangled pseudo spins $\tilde S=1/2$ and $\tilde S=0$. These pseudo-spins are built over frustrated clusters, similar to the kagomé building block, at the vertices of a triangular superlattice, the geometrical frustration intervening then at different scales.

Mots clés: quantum spin system; frustration; magnetism

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

Julien Robert, Virginie Simonet, Benjamin Canals, Rafik Ballou, Elsa Lhotel, et al.. Formation of collective spins in frustrated clusters. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2008, 77, pp.054421. ⟨10.1103/PhysRevB.77.054421⟩. ⟨hal-00179669v2⟩