Quantum spin dynamics of the honeycomb magnet K₂Co₂TeO₆ in high magnetic fields

2025/03/10 by Pilch, Patrick, Peedu, Laur, Nagel, Urmas +6
#FOS: Physical sciences #Strongly Correlated Electrons (cond-mat.str-el)

paper · doi:10.48550/arxiv.2503.07174

Abstract

We present terahertz spectroscopic measurements of quantum spin dynamics in the honeycomb magnet K₂Co₂TeO₆ as a function of temperature, polarization and in an external magnetic field applied in the honeycomb plane. Magnetic excitations are resolved below the magnetic ordering temperature of T_N = 12 K. In the applied magnetic field, we reveal characteristic field dependence not only for the magnetic excitations observed at zero field, but also a rich set of modes emerging in finite fields. The observed magnetic excitations exhibit clear dependence on the terahertz polarization, and characteristic features at field-induced phase transitions consistent with our high-field magnetization data. We cannot evidently resolve a continuumlike feature, even when the long-range magnetic order is presumably suppressed in the strong magnetic field, indicating that a Kitaev-type interaction, if existing, is subleading in this compound.

Related

• Field-induced spin continuum in twin-free Na₃Co₂SbO₆ revealed by magneto-THz spectroscopy
• Evidence for field induced quantum spin liquid behavior in a spin-1/2 honeycomb magnet
• Code and Data set for "Theory of Nonlinear Spectroscopy of Quantum Magnets"
• Dominant Kitaev Interaction and Field-induced Quantum Disordered Phase in the Cobaltate Na₂Co₂TeO₆
• Disorder-enriched magnetic excitations in the Kitaev quantum spin liquid candidate Na₂Co₂TeO₆