Strong Kitaev Interaction in BaCo_{2}(AsO_{4})_{2}

Area of Science:

• Condensed matter physics
• Quantum magnetism

Background:

• Honeycomb-lattice magnets are candidates for realizing novel quantum states.
• Understanding magnetic interactions is crucial for designing quantum materials.

Purpose of the Study:

• To investigate the magnetic interactions in BaCo_{2}(AsO_{4})_{2}.
• To elucidate the origin of its unusual magnetic properties.

Main Methods:

• Inelastic neutron scattering experiments.
• Anisotropic-exchange model development.
• Density-matrix renormalization group calculations.

Main Results:

• Unequivocal evidence for a dominant Kitaev interaction in BaCo_{2}(AsO_{4})_{2}.
• Anisotropic-exchange model successfully reproduces experimental data.
• Model is consistent with observed double-zigzag magnetic order and low saturation field.

Conclusions:

• The Kitaev interaction is the primary driver of magnetic behavior in BaCo_{2}(AsO_{4})_{2}.
• The findings provide insights into quantum magnetism in honeycomb materials.