Workshop "NMR, µSR, Mössbauer spectroscopies in the study of Fe-based and other unconventional high-Tc superconductors"
1D spin systems at high magnetic fields: from toy models to research tools
Toni Shiroka, ETH Zürich, Switzerland
Originally conceived as the simplest systems where to investigate unconventional superconductivity, low-dimensional spin systems have evolved into an independent object of study. Although simple, they still can demonstrate a broad spectrum of complex quantum physics: from collective excitations to quantum phase transitions, from geometric frustration to confinement and asymptotic freedom. Recent breakthroughs in material synthesis, as well as advances in theory and computational methods, have increased the interest and given new life to the field.
When a magnetic field is applied to a 1D spin system, the latter moves from a quantum fluctuation dominated regime to a field-induced ordered phase. Frustration and disorder change this simple picture by giving rise to rich, but largely unexplored phase diagrams. By using magnetic resonance techniques we investigate the impact of both these effects in a model case and show that frustration dominates the high-field ordered phase, where it accounts for the fractionalization of triplet excitations into solitons, eventually giving rise to a magnetic soliton lattice.