Phase Diagram of Ba$_{2}$NaOsO$_{6}$, a Mott insulator with strong spin orbit interactions

Abstract: We report $^{23}$Na nuclear magnetic resonance (NMR) measurements of the Mott insulator with strong spin-orbit interaction Ba${2}$NaOsO${6}$ as a function of temperature in different magnetic fields ranging from 7 T to 29 T. The measurements, intended to concurrently probe spin and orbital/lattice degrees of freedom, are an extension of our work at lower fields reported in Nat. Commun., v 8, 14407 (2017). We have identified clear quantitative NMR signatures that display the appearance of a canted ferromagnetic phase, which is preceded by local point symmetry breaking. We have compiled the field temperature phase diagram extending up to 29 T. We find that the broken local point symmetry phase extends over a wider temperature range as magnetic field increases.