Signatures of Floquet Engineering in the proximal Kitaev Quantum Spin Liquid H${}_3$LiIr${}_2$O${}_6$ by tr-RIXS

We present the first circularly polarized Floquet engineering time-resolved Resonant Inelastic X-ray Scattering (tr-RIXS) experiment in H${}_3$LiIr${}_2$O${}_6$, an iridium-based Kitaev system. Our calculations and experimental results are consistent with the modification of the low energy magnetic excitations in H${}_3$LiIr${}_2$O${}_6$ only during illumination by the laser pulse, consistent with the Floquet engineering of the exchange interactions. However, the penetration length mismatch between the X-ray probe and laser pump and the intrinsic complexity of Kitaev magnets prevented us from unequivocally extracting towards which ground H${}_3$LiIr${}_2$O${}_6$ was driven. We outline possible solutions to these challenges for Floquet stabilization and observation of the Kitaev Quantum Spin Liquid limit by RIXS.