Inspired by experiments on the magnetic field induced phases of the spin-orbit coupled two dimension ($2\text{D}$) Mott insulator $\alpha \text{−}{\mathrm{RuCl}}_3$, we study some general aspects of gapped $Z_2$ quantum spin liquids (QSL) enriched by lattice translation symmetry. We show that there are 12 distinct such phases with different implementations of translation symmetry. In some of these phases the vison excitations of this QSL may form topological Chern bands. We explore a phenomenological description of a putative $Z_2$ QSL as a candidate ground state at intermediate magnetic fields in $\alpha \text{−}{\mathrm{RuCl}}_3$. This state has broad continuum spectra in neutron scattering, a “bosonic” thermal Hall signal that goes to zero at zero temperature, and is naturally proximate to a zigzag magnetic ordered state, all of which are also seen in $\alpha \text{−}{\mathrm{RuCl}}_3$. On general grounds, continuum scattering will also be seen at multiple points in the Brillouin zone in this state.

Close

PrevNext

View figure in article

• Fractionalization
• Phenomenology
• Quantum spin liquid
• Thermal Hall effect
• Topological order
• Mott insulators