SchwingerBoson meanfield study of spin1/2 $J_1$$J_2$$J_{\chi}$ model in honeycomb lattice: thermal Hall signature
Abstract
We theoretically investigate, within the SchwingerBoson meanfield theory, the transition from a gapped $Z_{2}$ quantum spinliquid, in a $J_1$$J_2$ Heisenberg spin1/2 system in a honeycomb lattice, to a chiral $Z_2$ spin liquid phase under the presence of timereversal symmetry breaking scalar chiral interaction (with amplitude $J_{\chi}$), with nontrivial Chern bands of the excitations. We numerically obtain a phase diagram of such $J_1$$J_2$$J_{\chi}$ system, where different phases are distinguished based on the gap and the nature of excitation spectrum, topological invariant of the excitations, the nature of spinspin correlation and the symmetries of the meanfield parameters. The chiral $Z_2$ state is characterized by nontrivial Chern number of the excitation bands and lack of longrange magnetic order, which leads to large thermal Hall coefficient.
 Publication:

arXiv eprints
 Pub Date:
 August 2021
 arXiv:
 arXiv:2108.08801
 Bibcode:
 2021arXiv210808801M
 Keywords:

 Condensed Matter  Strongly Correlated Electrons
 EPrint:
 12 pages, 7 figures. Comments welcome