Gapless chiral spin liquid from coupled chains on the kagome lattice

Abstract

Using a perturbative renormalization group approach, we show that the extended (J_1-J_2-J_dJ1−J2−Jd) Heisenberg model on the kagome lattice with a staggered chiral interaction (J_\chiJχ) can exhibit a gapless chiral quantum spin liquid phase. Within a coupled-chain construction, this phase can be understood as a chiral sliding Luttinger liquid with algebraic decay of spin correlations along the chain directions. We calculate the low-energy properties of this gapless chiral spin liquid using the effective field theory and show that they are compatible with the predictions from parton mean-field theories with symmetry-protected line Fermi surfaces. These results may be relevant to the state observed in the kapellasite material.