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arXiv:1604.07829 · Physical review. B./Physical review. B

Chiral spin liquid and quantum criticality in extended S=12 Heisenberg models on the triangular lattice

Alexander Wietek, Andreas Martin Läuchli

Published Jan 24, 2017• 132 citations
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Abstract

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.

DOI
10.1103/physrevb.95.035141

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We study the S=1/2S=1/2S=1/2 Heisenberg model on the triangular lattice with nearest- and next-nearest-neighbor interactions J1{J}_{1}J1​ and J2{J}_{2}J2​ with the density matrix renormalization group, on long open cylinders with widths up to nine lattice spacings. In an intermediate J2{J}_{2}J2​ region $0.06\ensuremath{\lesssim}{J}_{2}/{J}_{1}\ensuremath{\lesssim}0.17$, we find evidence for a spin liquid (SL) state with short range spin-spin, bond-bond, and chiral correlation lengths, bordered by a classical ${120}^{\ensuremath{\circ}}$ N\'eel ordered state at small J2{J}_{2}J2​ and by a two sublattice collinear magnetically ordered state at larger J2{J}_{2}J2​. Focusing on J2/J1=0.1{J}_{2}/{J}_{1}=0.1J2​/J1​=0.1, we find a number of signatures of a gapped SL phase.
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