Bibliographic Details
| Title: |
Monopole excitations in the $U(1)$ Dirac spin liquid on the triangular lattice |
| Authors: |
Budaraju, Sasank, Parola, Alberto, Iqbal, Yasir, Becca, Federico, Poilblanc, Didier |
| Source: |
Phys. Rev. B 111, 125150 (2025) |
| Publication Year: |
2024 |
| Collection: |
Condensed Matter |
| Subject Terms: |
Condensed Matter - Strongly Correlated Electrons |
| More Details: |
The $U(1)$ Dirac spin liquid might realize an exotic phase of matter whose low-energy properties are described by quantum electrodynamics in $2+1$ dimensions, where gapless modes exists but spinons and gauge fields are strongly coupled. Its existence has been proposed in frustrated Heisenberg models in presence of frustrating super-exchange interactions, by the (Abrikosov) fermionic representation of the spin operators [X.-G. Wen, \href{https://doi.org/10.1103/PhysRevB.65.165113}{Phys. Rev. B {\bf 65}, 165113 (2002)}], supplemented by the Gutzwiller projection. Here, we construct charge-$Q$ monopole excitations in the Heisenberg model on the triangular lattice with nearest- ($J_1$) and next-neighbor ($J_2$) couplings. In the highly frustrated regime, singlet and triplet monopoles with $Q=1$ become gapless in the thermodynamic limit; in addition, the energies for generic $Q$ agree with field-theoretical predictions, obtained for a large number of gapless fermion modes. Finally, we consider localized gauge excitations, in which magnetic $\pi$-fluxes are concentrated in the triangular plaquettes (in analogy with $\mathbb{Z}_2$ visons), showing that these kind of states do not play a relevant role at low energies. All our findings lend support to a stable $U(1)$ Dirac spin liquid in the $J_1-J_2$ Heisenberg model on the triangular lattice.
Comment: 10 pages, 7 figures, 1 table |
| Document Type: |
Working Paper |
| DOI: |
10.1103/PhysRevB.111.125150 |
| Access URL: |
http://arxiv.org/abs/2410.18747 |
| Accession Number: |
edsarx.2410.18747 |
| Database: |
arXiv |
