Distorted honeycomb magnet edges closer to a quantum spin liquid

Researchers at Oak Ridge National Laboratory have synthesized and studied a new magnetic material, potassium cobalt arsenate, which features cobalt atoms arranged in a two-dimensional honeycomb lattice. This structure was designed to realize a quantum spin liquid state—a highly sought-after magnetic phase where spins remain disordered even at extremely low temperatures, potentially enabling exotic particles and robust quantum technologies. Although the material’s honeycomb lattice was confirmed, it exhibited slight distortions, and experiments showed that below about 14 kelvin, the cobalt spins settled into an ordered pattern rather than remaining fluid as a quantum spin liquid would. Neutron scattering and computer simulations revealed that while the material exhibited the theoretically predicted Kitaev interactions—key to stabilizing quantum spin liquids—these interactions were weaker than conventional magnetic forces, causing the spins to freeze. Despite not achieving a quantum spin liquid state, the material lies near a critical tipping point. The researchers suggest that modest modifications, such as chemical doping, applying pressure, or strong magnetic fields, could enhance the Kita