Ultrafast renormalization of the magnetic continuum in the proximal Kitaev quantum spin liquid H ₃ LiIr ₂ O ₆ by tr-RIXS [Invited]

We present the first circularly polarized non-resonant pump 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. We discuss these results in a cooperative framework between the Floquet engineering of the exchange interactions and the dynamic renormalization of electron-electron correlations. However, the penetration length mismatch between the X-ray probe and laser pump and the intrinsic complexity of Kitaev magnets prevents us from unequivocally extracting towards which ground state H ₃ LiIr ₂ O ₆ is driven. We outline possible solutions to these challenges for light-driven stabilization and observation of the Kitaev quantum spin liquid limit by RIXS.