# Vanishing spin gap in a competing spin-liquid phase in the kagome Heisenberg antiferromagnet

@article{Iqbal2014VanishingSG, title={Vanishing spin gap in a competing spin-liquid phase in the kagome Heisenberg antiferromagnet}, author={Yasir Iqbal and Didier Poilblanc and Federico Becca}, journal={Physical Review B}, year={2014}, volume={89}, pages={020407-020407} }

We provide strong numerical evidence, using improved variational wave functions, for a ground state with vanishing spin gap in the spin-$1/2$ quantum Heisenberg model on the kagome lattice. Starting from the algebraic $U(1)$ Dirac spin liquid state proposed by Ran et al. [Phys. Rev. Lett. 98, 117205 (2007)] and iteratively applying a few Lanczos steps, we compute the lowest $S=2$ excitation constructed by exciting spinons close to the Dirac nodes. Our results are compatible with a vanishing…

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