Exotic quantum phases have been proposed in magnetic Mott insulators with strong spin-orbit coupling. Our recent nuclear magnetic resonance (NMR) studies of the Mott insulator Ba2NaOsO6 established that local lattice distortions precede the onset of canted ferromagnetic order^1,2. It was suggested that lattice distortions are a manifestation of the orbital order that drives the magnetism in this class of materials³. To decipher the microscopic nature of the putative orbital order, we investigate different lattice distortion models and calculate their associated NMR observables. Results of various distortion models will be discussed in this talk.

[1] Lu, L., et al. "Magnetism and local symmetry breaking in a Mott insulator with strong spin orbit interactions." Nature communications 8 (2017): 14407.
[2] Liu, W., et al. "Nature of lattice distortions in the cubic double perovskite Ba 2 NaOsO 6." Physical Review B 97.22 (2018): 224103.
[3] Chen, Gang, Rodrigo Pereira, and Leon Balents. "Exotic phases induced by strong spin-orbit coupling in ordered double perovskites." Physical Review B 82.17 (2010): 174440.