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Optimized RVB states of the 2-d antiferromagnet: Ground state and excitation spectrum

Yong-Cong Chen·Kai Xiu
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Abstract

The Gutzwiller projection of the Schwinger-boson mean-field solution of the 2-d spin-1/2 antiferromagnet in a square lattice is shown to produce the optimized, parameter-free RVB ground state. We get $-0.6688J$/site and $0.311$ for the energy and the staggered magnetization. The spectrum of the excited states is found to be linear and gapless near $\bk\cong 0$. Our calculation suggests, upon breaking of the rotational symmetry, $ε_{\bk}\cong 2JZ_{r} \sqrt{1-γ_{\bk}^{2}}$ with $Z_{r}\cong 1.23$. To appear in Phys. Lett. A (1993).

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Yong-Cong Chen, Kai Xiu. 1993-09-27. Optimized RVB states of the 2-d antiferromagnet: Ground state and excitation spectrum. https://doi.org/10.1016/0375-9601(93)90391-c

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