We theoretically investigate, within the Schwinger-Boson mean-field theory, the transition from a gapped Z2 quantum spin-liquid, in a J1-J2 Heisenberg spin-1/2 system in a honeycomb lattice, to a chiral Z2 spin Liquid phase under the presence of time-reversal symmetry breaking scalar chiral interaction (with amplitude Jχ), with non-trivial Chern bands of the excitations. We numerically obtain a phase diagram of such J1-J2-Jχ system, where different phases are distinguished based on the gap and the nature of excitation spectrum, topological invariant of the excitations, the nature of spin-spin correlation and the symmetries of the mean-field parameters. The chiral Z2 state is characterized by non-trivial Chern number of the excitation bands and lack of long-range magnetic order, which leads to large thermal Hall coefficients.
Zoom link: https://us06web.zoom.us/j/84602931542?pwd=cm1TODVBZWZySzAyeXJBR2dQUWJ3Zz09
Meeting ID: 846 0293 1542