Static and dynamical signatures of Dzyaloshinskii-Moriya interactions in the Heisenberg model on the kagome lattice
Francesco Ferrari, Sen Niu, Juraj Hasik, Yasir Iqbal, Didier Poilblanc, Federico Becca
SciPost Phys. 14, 139 (2023) · published 1 June 2023
- doi: 10.21468/SciPostPhys.14.6.139
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Abstract
Motivated by recent experiments on Cs$_2$Cu$_3$SnF$_{12}$ and YCu$_{3}$(OH)$_{6}$Cl$_{3}$, we consider the ${S=1/2}$ Heisenberg model on the kagome lattice with nearest-neighbor super-exchange $J$ and (out-of-plane) Dzyaloshinskii-Moriya interaction $J_D$, which favors (in-plane) ${{\bf Q}=(0,0)}$ magnetic order. By using both variational Monte Carlo and tensor-network approaches, we show that the ground state develops a finite magnetization for $J_D/J \gtrsim 0.03 \mathrm{-} 0.04$; instead, for smaller values of the Dzyaloshinskii-Moriya interaction, the ground state has no magnetic order and, according to the fermionic wave function, develops a gap in the spinon spectrum, which vanishes for $J_D \to 0$. The small value of $J_D/J$ for the onset of magnetic order is particularly relevant for the interpretation of low-temperature behaviors of kagome antiferromagnets, including ZnCu$_{3}$(OH)$_{6}$Cl$_{2}$. For this reason, we assess the spin dynamical structure factor and the corresponding low-energy spectrum, by using the variational Monte Carlo technique. The existence of a continuum of excitations above the magnon modes is observed within the magnetically ordered phase, with a broad peak above the lowest-energy magnons, similarly to what has been detected by inelastic neutron scattering on Cs$_{2}$Cu$_{3}$SnF$_{12}$.
Cited by 11
Authors / Affiliations: mappings to Contributors and Organizations
See all Organizations.- 1 2 Francesco Ferrari,
- 3 Sen Niu,
- 4 Juraj Hasik,
- 2 Yasir Iqbal,
- 3 Didier Poilblanc,
- 5 Federico Becca
- 1 Goethe-Universität Frankfurt am Main / Goethe University Frankfurt
- 2 भारतीय प्रौद्योगिकी संस्थान मद्रास / Indian Institute of Technology Madras [IITM]
- 3 Laboratoire de Physique Théorique Toulouse [LPT]
- 4 Universiteit van Amsterdam / University of Amsterdam [UvA]
- 5 Università degli Studi di Trieste / University of Trieste [UNITS]
- Centro Internazionale di Fisica Teorica Abdus Salam / Abdus Salam International Centre for Theoretical Physics [ICTP]
- Agence Nationale de la Recherche [ANR]
- Alexander von Humboldt-Stiftung / Alexander von Humboldt Foundation
- Department of Science and Technology, Ministry of Science and Technology (through Organization: विज्ञान एवं प्रौद्योगिकी विभाग / Department of Science and Technology [DST])
- Deutsche Forschungsgemeinschaft / German Research FoundationDeutsche Forschungsgemeinschaft [DFG]
- Grand Équipement National De Calcul Intensif (through Organization: Grand Equipement National de Calcul Intensif [GENCI])
- Horizon 2020 (through Organization: European Commission [EC])
- Indian Institute of Technology Madras
- International Centre for Theoretical Sciences
- National Science Foundation [NSF]
- Simons Foundation