Numerical evidence of a chiral spin liquid in the spin-1/2 honeycomb XY model*

The frustrated XY model on the honeycomb lattice has received lots of attentions because of the potential chiral spin liquid (CSL) in the intermediate region. Using density matrix renormalization group method on the cylinder system, we study the spin-1/2 XY model with first-neighbor (J1) and second-neighbor (J2) interactions, and in the presence of a chiral term. We obtain a quantum phase transition and a non-magnetic phase with finite scalar chiral order when we turn on a small chiral interaction. Further analysis of the entanglement spectrum is consistent with the Kalmeyer-Laughlin CSL in this region.