The study of low dimensional spin-1/2 quantum systems has been a very prolific field of condensed matter physics during the last decades. The family of vanadates, in particular, has provided a rich variety of compounds with different behaviors and topologies.
In this framework, the sole consideration of the topology of a compound, usually based on a simple analysis of the distances separating the magnetic centers, is often incomplete and even misleading.
In this work, the magnetic properties of the layered compound CsV2O5 have been investigated using density-functional calculations. Through an extensive use of the broken symmetry formalism in DFT, we propose a new picture of CsV2O5 where “structural” and “magnetic” dimers are distinct from each other. More generally, we demonstrate that non magnetic bridging units, such as [V5+O4]3- tetrahedra, play a preponderant role in mediating strong and long ranged anti-ferromagnetic interactions in this system.
Centre Interdisciplinaire de Nanoscience de Marseille – CNRS, Campus de Luminy, Marseille