Ixert D, Tischler T, Schmidt KP (2015)
Publication Status: Published
Publication Type: Journal article
Publication year: 2015
Publisher: AMER PHYSICAL SOC
Book Volume: 92
Journal Issue: 17
DOI: 10.1103/PhysRevB.92.174422
We use nonperturbative linked-cluster expansions to determine the ground-state energy per site of the spin-one Heisenberg model on the kagome lattice. To this end, a parameter is introduced allowing us to interpolate between a fully trimerized state and the isotropic model. The ground-state energy per site of the full graph decomposition up to graphs of six triangles (18 spins) displays a complex behavior as a function of this parameter close to the isotropic model which we attribute to divergencies of partial series in the graph expansion of quasi-1D unfrustrated chain graphs. More concretely, these divergencies can be traced back to a quantum critical point of the one-dimensional unfrustrated chain of coupled triangles. Interestingly, the reorganization of the nonperturbative linked-cluster expansion in terms of clusters with enhanced symmetry yields a ground-state energy per site of the isotropic two-dimensional model that is in quantitative agreement with other numerical approaches in favor of a spontaneous trimerization of the system. Our findings are of general importance for any nonperturbative linked-cluster expansion on geometrically frustrated systems.
APA:
Ixert, D., Tischler, T., & Schmidt, K.P. (2015). Nonperturbative linked-cluster expansions for the trimerized ground state of the spin-one kagome Heisenberg model. Physical Review B, 92(17). https://doi.org/10.1103/PhysRevB.92.174422
MLA:
Ixert, Dominik, Tobias Tischler, and Kai Phillip Schmidt. "Nonperturbative linked-cluster expansions for the trimerized ground state of the spin-one kagome Heisenberg model." Physical Review B 92.17 (2015).
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