Spatial periodicity of the spin-1/2 Heisenberg antiferromagnetic chain with competing interactions
Chen Zeng, John B. Parkinson
A resonating-valence-bond (RVB) wave function including the nearest- and next-nearest-neighbor singlets is proposed for the S=1/2 Heisenberg antiferromagnetic chain with competing interactions. A variational upper bound for the ground-state energy is provided. Spin-spin correlation functions are calculated analytically and compared with those obtained by finite-size exact diagonalizations. Within this RVB ansatz, the spatial periodicity of the ground-state wave function, which is defined as the phase modulation of spin-spin correlation functions, is found to undergo a discontinuous transformation from two-fold to four-fold as the relative strength of the competing interactions is varied. We further discuss this transformation in terms of the Marshall-Peierls sign rule.
Physical review. B, Condensed matter•May 1, 1995•23 citations