Category: Highlights

  Quantum spin liquids form an exotic class of quantum phases of matter, accompanied by emergent gauge fields, topological order and fractionalized excitations, with strong interaction effects and long-range entanglement.  The recently discovered material Ca10Cr7O28 shows strong indications of hosting such a novel phase of matter, but with properties that sets it apart from any previously studied quantum spin liquid. In this work, we make a crucial step towards understanding the nature and origin of the spin liquid behaviour in Ca10Cr7O28. Using a combination of Monte Carlo and molecular dynamics simulation, and spin-wave calculations, we carry out a comprehensive study of a bilayer breathing kagome model derived from experiment. We Continue Reading →

  The Curie-Weiss law is widely used to estimate the strength of frustration in spin liquid materials. However, the Curie-Weiss law was originally derived as an estimate of magnetic correlations close to a mean-field phase transition, which – by definition – is absent in spin liquids. Consequently, certain materials were reported to exhibit deviations from the Curie-Weiss law, making a conclusive determination of their Curie-Weiss temperature challenging, especially when the high-temperature regime becomes inaccessible in experiments. In this work, we show that the concept of a ”Curie-law crossover” (see Fig.1) provides an accurate description of the thermodynamic properties in spin liquids. We study the generic aspect of the Curie-law crossover Continue Reading →

New discoveries are often made on the border between different disciplines. One major discipline in solid state physics is dedicated to quantum spin liquids, an unconventional state of matter accompanied by emergent gauge fields, topological order, and fractionalized excitations. Another concept is that of spin nematics, a magnetically ordered state dominated by quadrupole moments, which breaks spin-rotation symmetry by selecting an axis, while not choosing a particular direction. Usually seen as two separate areas of study, we are interested in combining those two disciplines, by asking the question: “What happens, when a spin nematic and a spin liquid meet?” To answer this question, we showed that the S=1 Kitaev model Continue Reading →