Abstract
We present the dynamical spin structure factor of the antiferromagnetic spin-12 J1-J2 Heisenberg model on a triangular lattice obtained from large-scale matrix-product state simulations. The high frustration due to the combination of antiferromagnetic nearest- and next-nearest-neighbor interactions yields a rich phase diagram. We resolve the low-energy excitations both in the 120∘ ordered phase and in the putative spin-liquid phase at J2/J1=0.125. In the ordered phase, we observe an avoided decay of the lowest magnon branch, demonstrating the robustness of this phenomenon in the presence of gapless excitations. Our findings in the spin-liquid phase chime with the field-theoretical predictions for a gapless Dirac spin liquid, in particular the picture of low-lying monopole excitations at the corners of the Brillouin zone. We comment on possible practical difficulties of distinguishing proximate liquid and solid phases based on the dynamical structure factor.
Original language | English |
---|---|
Article number | L220401 |
Journal | Physical Review B |
Volume | 108 |
Issue number | 22 |
DOIs | |
State | Published - 1 Dec 2023 |