Topological phases in spin-orbit-coupled strongly correlated systems

Abstract

Quantum spin liquids are systems of interacting spins that remain disordered at zero temperature due to strong quantum fluctuations. Such systems are characterized by an exotic excitation spectrum with deconfined fractional quasiparticles and emergent gauge fields. The goal of this PhD project is to study a theoretical model for Mott-insulating double perovskites with strong spin-orbit coupling. This model is a realistic model that may stabilize a gapless spin liquid ground state with Majorana fermion excitations. For the research internship we propose that the PhD candidate will work in collaboration with Prof. Maria Daghofer to investigate the spin and orbital excitation spectrum of the model using a combination of analytical and numerical methods. The idea is to search for clear signatures of spin liquid behavior that could be observed in inelastic neutron scattering and resonant inelastic x-ray scattering experiments. In addition, we intend to extend the results to the case of itinerant electrons on the double perovskite model and analyze possible transitions between topological phases of weakly interacting electrons and the spin liquid phase. (AU)