Abstract
We propose a finite-temperature phase diagram for the two-dimensional spin-1/2 J1-J2 XXZ antiferromagnet on a triangular lattice. Our analysis, based on a composite fermion representation, yields several phases. This includes a zero-temperature helical spin liquid with N=6 anisotropic Dirac cones, and with nonzero vector chirality implying a broken Z2 symmetry. It is terminated at T=0 by a continuous quantum phase transition to a 120° ordered state around J2/J1≈0.089 in the XX limit; these phases share a double degeneracy, which persists to finite T above the helical spin liquid. By contrast, at J2/J1≃0.116, the transition into a stripe phase appears as first order. We further discuss experimental and numerical consequences of the helical order and the anisotropic nature of the Dirac dispersion.
| Original language | English (US) |
|---|---|
| Article number | 024430 |
| Journal | Physical Review B |
| Volume | 102 |
| Issue number | 2 |
| DOIs | |
| State | Published - Jul 1 2020 |
Bibliographical note
Publisher Copyright:© 2020 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Open access publication funded by the Max Planck Society.