2017/05/31 by Shou-Shu Gong, W. Zhu, J. -X. Zhu +2 · 1 citation
Physics and Astronomy · #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.96.075116
published as Phys. Rev. B 96, 075116 (2017) · 10 pages, 14 figures
arxiv created 2017/08/11 · arxiv updated 2017/08/16
We study the spin-1/2 Heisenberg model on the triangular lattice with the nearest-neighbor J1 > 0, the next-nearest-neighobr J2 > 0 Heisenberg interactions, and the additional scalar chiral interaction Jχ(Si × Sj) ⋅ Sk for the three spins in all the triangles using large-scale density matrix renormalization group calculation on cylinder geometry. With increasing J2 (J2/J1 ≤ 0.3) and Jχ (Jχ/J1 ≤ 1.0) interactions, we establish a quantum phase diagram with the magnetically ordered 120∘ phase, stripe phase, and non-coplanar tetrahedral phase. In between these magnetic order phases, we find a chiral spin liquid (CSL) phase, which is identified as a ν= 1/2 bosonic fractional quantum Hall state with possible spontaneous rotational symmetry breaking. By switching on the chiral interaction, we find that the previously identified spin liquid in the J1 - J2 triangular model (0.08 \lesssim J2/J1 \lesssim 0.15) shows a phase transition to the CSL phase at very small Jχ. We also compute spin triplet gap in both spin liquid phases, and our finite-size results suggest large gap in the odd topological sector but small or vanishing gap in the even sector. We discuss the implications of our results to the nature of the spin liquid phases.