Valence bond ground state of a spinel oxide MgTi₂O₄

Natalia Perkins

Max-Planck-Institute for the Physics of Complex Systems, Nöthnitzer Str. 38, D-01187 Dresden, Germany

We consider the physical realization of a valence bond crystal (VBC) in threefold-orbitally-degenerate S=1/2 pyrochlore lattices, like in MgTi2O4. We argue that, remarkably, such a novel phase can be realized on a pyrochlore lattice because of orbital degeneracy.