Bond disorder in extended Heisenberg-Kitaev models: Spin textures and in-gap states in the high-field regime

Motivated by experimental results obtained for the layered Kitaev magnet $\ensuremath{\alpha}$-RuCl${}_{3}$, the authors investigate here the effect of quenched disorder in extended Heisenberg-Kitaev models. Defects are shown to introduce local spin textures and to induce magnetic states inside the excitation gap of the high-field phase, with both phenomena strongly depending on the direction of the applied magnetic field. The study highlights the nontrivial defect physics in strongly spin-orbit coupled magnets in general, and Kitaev materials in particular.