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Download fileDestruction of valence-bond order in a S=1/2 sawtooth chain with a Dzyaloshinskii-Moriya term
journal contribution
posted on 07.08.2018, 13:28 authored by Zhihao Hao, Yuan Wan, Ioannis RousochatzakisIoannis Rousochatzakis, Julia Wildeboer, A. Seidel, Frederic Mila, O. TchernyshyovA small value of the spin gap in quantum antiferromagnets with strong frustration makes them susceptible to nominally small deviations from the ideal Heisenberg model. One such perturbation, the anisotropic Dzyaloshinskii-Moriya (DM) interaction, is an important perturbation for the S=1/2 kagome antiferromagnet, one of the current candidates for a quantum-disordered ground state. We study the influence of the DM term in a related one-dimensional system, the sawtooth chain, which has valence-bond order in its ground state. Through a combination of analytical and numerical methods, we show that a relatively weak DM coupling, 0.115J, is sufficient to destroy the valence-bond order, close the spin gap, and turn the system into a Luttinger liquid with algebraic spin correlations. A similar mechanism may be at work in the kagome antiferromagnet. © 2011 American Physical Society.
Funding
Y.W. was supported by William Bently Gardner. A.S. and J.W. were supported by the National Science Foundation under NSF Grant No. DMR-0907793.
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