Effect of spin-orbit coupling on magnetic and orbital order in MgV2O4

Recent measurements on MgV2O4 single crystals have reignited the debate on the role of spin-orbit (SO) coupling in dictating the orbital order in vanadium spinel systems. Density functional theory calculations were performed using the full-potential linearized augmented-plane-wave method within the local spin density approximation (LSDA), Coulomb correlated LSDA (i.e. LSDA + U), and with SO interaction (LSDA + U + SO) to study the magnetic and orbital ordering in the low temperature phase of MgV2O4. It is observed that, in the experimental antiferromagnetic phase, the spin-orbit coupling affects the orbital order differently in alternate V-atom chains along the c-axis. This observation is consistent with the experimental prediction that the effect of spin-orbit coupling is intermediate between those in the cases of ZnV2O4 and MnV2O4.