Magnetic field and frustration induced quantum spin liquid in a J₁-J₃ honeycomb XY model

Recent experimental studies have shown that applying a magnetic field to honeycomb cobaltates leads to suppression of magnetic order, resulting in a broad continuum observed in THz spectroscopy. Motivated by these observations, we construct a parton mean-field theory model for the J₁-J₃ XY spin model on the honeycomb lattice in the presence of anisotropies. We employ several numerical techniques to find the ground state and study its properties in the presence of an external Zeeman field. Tuning a phenomenological parameter which enhances the effect of quantum fluctuations relative to ordering tendencies, we find the existence of an intermediate Dirac QSL with spin-rotation symmetry breaking. We analyze the dynamic spin-structure factor in this QSL phase, in the absence and presence of a magnetic field, and compare it to experimental data.