Revealing spin gap through magnetic dynamics in one candidate Kitaev material

The Kitaev quantum spin liquid stands out as a promising platform for advancing topological quantum computing. Na₂Co₂TeO₆, identified as a candidate for realizing this unique quantum state, exhibits versatile magnetic transitions, manifesting 2D and 3D magnetic orders at distinct temperatures [1]. Time-resolved studies of magnetism on ultrafast timescales offer the possibility to trace the evolution of magnetism and provide an exciting opportunity for ultrafast optical manipulation of magnetic order. Using time-resolved resonant X-ray scattering, we uncover the magnetic dynamics in Na₂Co₂TeO₆ [2]. Our results unambiguously demonstrate that light excitation can suppress spin order in a nonthermal way while barely perturbing structural order. Intriguingly, the decay time extends beyond several tens of picoseconds, while the recovery time reaches several nanoseconds, notably longer than observed in other magnetic materials. Our results provide insight into the characteristic magnetic dynamics of candidate Kitaev materials and underscore the potential of time-resolved resonant X-ray scattering for probing small spin gaps that conventional techniques find challenging to access.





References:

[1] W. J. Chen, et al., Phys. Rev. B 103, L180404 (2021).

[2] X. Y. Jiang, Y. Y. Peng et al, in preparation.