Resonant inelastic x-ray scattering (RIXS) study to investigate low-energy magnetic and spin-orbit excitations of Ir2O9 dimers in Ba3ZrIr2O

The 6H-hexagonal perovskite iridates Ba3M4+Ir2O9 with Ir4+ ions on a triangular lattice have been serving as a potential paradigm for exploring a diverse spectrum of novel quantum magnetism. The M = Zr & Ti members of this series, become extremely promising to study quantum magnetism. Our combined magnetic, thermodynamic, and µSR characterizations on these compounds clearly refute any static magnetic ordering, despite having sizeable antiferromagnetic Ir-Ir exchange, in Ba3ZrIr2O9 and Ba3TiIr2O9 down to 40 mK and point towards emergence of a quantum spin liquid like dynamic magnetic ground state. Moreover, our low-T specific heat suggests presence of gapless spinon excitations in both compounds. We therefore propose to carry out resonant inelastic x-ray scattering (RIXS) at the Ir-L3 edge of both compounds to shed insights into the correlated quantum states and associated low-lying magnetic excitations borne out of the interplay between emergent degrees of freedom in these two Ir-based