Chiral spin liquid and quantum criticality in extended S =1/2 Heisenberg models on the triangular lattice

We investigate the ${J}_{1}\ensuremath{-}{J}_{2}$ 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 ${120}^{\ensuremath{\circ}}$ N\'eel ordered and a noncoplanar tetrahedrally ordered phase. Furthermore we discuss the nature of the spin-disordered intermediate phase in the ${J}_{1}\ensuremath{-}{J}_{2}$ 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 ${120}^{\ensuremath{\circ}}$ magnetically ordered phase and a putative ${\mathbb{Z}}_{2}$ spin liquid.