Impurity Effects in Spinon Majorana Materials

Recently, magnonic materials have seen a rejuvenated interest in the context of the non-trivial topological band structure of magnonic excitations in materials that follows from a non-Bravais crystal lattice. This non-trivial band structure has interesting signatures in various transport properties of magnon topological materials. In addition, the presence of Dirac points in the excitation spectrum leads to graphene-like impurity bound states. Here, we explore the extreme case of S=1/2 magnetic atoms with the most pronounced magnetic fluctuations and apply a familiar Majorana fermion representation, alternative to the usual Holstein-Primakoff transformation applicable to the higher-spin case. We obtain a self-consistent mean-field fermionic description of these quantum magnets with fermionic excitations -- spinons. For non-Bravais lattices, such as the honeycomb lattice, we explore the band structure of the fermionic excitations -- spinons, and their repercussions on impurity bound states and magnetic susceptibility. The system is readily amenable to quantum simulations using commercially available quantum processors.