Nobel laureate Paul W. Anderson proposed that high-temperature superconductivity is related to an exotic quantum state now known as quantum spin liquid, in which magnetic moments behave like a liquid and do not freeze or order even at absolute zero. They are promising materials for topological quantum computers, which would be based on the particle-like excited states found in quantum spin liquids. Tantalum (IV) sulphide (1T-TaS2) is an important model system with semiconductor properties, but scientists have been searching for an explanation of its unusual magnetic properties for more than 40 years. A team of Slovenian researchers undertook the first muon-spin-relaxation (μSR) measurements on polycrystalline 1T-TaS2 on the MuSR instrument, probing the magnetic properties of the low-temperature spin state and the physics behind the quantum spin liquid on a triangular lattice. Their findings confirmed the prediction of QSL in 1T-TaS2, which has been unresolved for over 40 years, but also raise questions about the nature of emergent states out of QSLs.
Related publication: M. Klanjšek et al. “A high-temperature quantum spin liquid with polaron spins" Nature Physics 13(2017), 1130–1134, DOI: 10.1038/nphys4212