Magnetic interactions and possible quantum paraelectricity in spin liquid candidate H₃LiIr₂O₆

H₃LiIr2O₆ was recently synthesized and found to be potentially a quantum spin liquid. We studied the crystal structure and magnetic interactions of this material by first principles calculations, and further studied the resulting phase of the obtained pseudospin model by exact diagonalizations. We found that the dominant magnetic interaction of this material is ferromagnetic Kitaev interaction, but residue (further neighbor) Heisenberg interactions would still produce a zigzag magnetic order. We then studied the quantum effect of the hydrogen ions(protons), and found that the electric dipoles of O-H-O "hydrogen bonds" are disordered by strong quantum fluctuations. The electric dipole fluctuations can renormalize the magnetic interactions and potentially lead to a Kitaev spin liquid state in this material. We thus propose that H₃LiIr₂O₆ is a quantum spin liquid promoted by quantum paraelectricity.