Exploring 3d systems for quantum spin liquids
05 May 2026
Using neutron and muon experiments, a team from South Korea, the USA and ISIS investigated the structure under ambient conditions and dynamics of a magnetic field-induced intermediate state of Na2Co2TeO6, which is a 3d system and leading candidate for hosting a Kitaev quantum spin liquid.
Quantum spin liquid materials have magnetic properties that don’t behave the same as standard magnetic materials. Instead of the well-ordered characteristics of ferromagnets, such as those we put on our fridge, these materials are disordered and the electrons within them connect magnetically via quantum entanglement.
Although quantum spin liquids exist in theory and have been modelled by scientists, it has not been possible to produce them experimentally or to find them in nature.
A model produced by the theoretical physicist Alexei Kitaev in 2009 was able to demonstrate some foundational principles for quantum spin liquids. However, the magnetic interactions it described required an environment that scientists have been unable to produce experimentally without the materials reverting to a conventionally ordered magnetic state.
Recently, compounds that have a honeycomb lattice that incorporate edge-sharing octahedra with 3d cobalt (Co) ions have emerged as viable candidates for hosting these Kitaev interactions. Among these, Na2Co2TeO6 has been identified as a leading possibility. However, like other candidate Kitaev systems, Na2Co2TeO6 exhibits long-range magnetic order at low temperatures. However, this order can be supressed by applying a magnetic field of 5.7 T.
In this study, nominated as an ‘Editors’ Suggestion’ in Physical Review B, the team, led by Sungkyun Choi and Kwang-Yong Choi from Sungkyunkwan University in South Korea, studied the structure under ambient conditions and dynamics of Na2Co2TeO6 under high magnetic fields using neutron techniques at ISIS and muon spectroscopy at PSI.
These findings indicate the emergence of a spin liquid–like state, highlighting the potential of this system for exploring magnetic field-induced quantum phenomena associated with Kitaev magnetism.
Matthias Gutmann, ISIS
Working with Matthias Gutmann, Christian Balz, Ross Stewart and the cryogenics team at ISIS, they were able to use inelastic neutron scattering on LET to observe low energy magnons and high energy spinons in high magnetic fields. These are indicative of Kitaev magnetism and a spin liquid-like state.
Neutron diffraction on SXD enabled them to resolve long-standing ambiguities about the crystal structure, revealing a triangular layer of sodium ions that can better stabilise the spin liquid state observed under magnetic fields.
“These findings indicate the emergence of a spin liquid–like state, highlighting the potential of this system for exploring magnetic field-induced quantum phenomena associated with Kitaev magnetism,” explains Matthias.
This research is paving the way in the search for similar materials with 3d electron systems hosting Kitaev quantum spin liquids, offering a new and distinct energy landscape for exploring Kitaev magnetism compared to 4d and 5d systems.
The full study can be found at DOI: 10.1103/1vbc-5tlh
