Chiral spin liquid and quantum criticality in extended $S=\frac{1}{2}$ Heisenberg models on the triangular lattice

Chiral spin liquid and quantum criticality in extended $S = \frac{1}{2}$ Heisenberg models on the triangular lattice

Alexander Wietek and Andreas M. Läuchli

Phys. Rev. B 95, 035141 – Published 24 January 2017

Abstract

We investigate the $J_{1} - J_{2}$ Heisenberg model on the triangular lattice with an additional scalar chirality term and show that a chiral spin liquid is stabilized in a sizable region of the phase diagram. This topological phase is situated in between a coplanar $120^{\circ}$ Néel ordered and a noncoplanar tetrahedrally ordered phase. Furthermore we discuss the nature of the spin-disordered intermediate phase in the $J_{1} - J_{2}$ model. We compare the ground states from exact diagonalization with a Dirac spin liquid wave function and propose a scenario where this wave function describes the quantum critical point between the $120^{\circ}$ magnetically ordered phase and a putative $Z_{2}$ spin liquid.