• DOI:10.1103/PhysRevB.53.2213
• Corpus ID: 12135095

Numerical evidence for the spin-Peierls state in the frustrated quantum antiferromagnet.

@article{Leung1996NumericalEF,
  title={Numerical evidence for the spin-Peierls state in the frustrated quantum antiferromagnet.},
  author={Leung and Lam},
  journal={Physical review. B, Condensed matter},
  year={1996},
  volume={53 5},
  pages={
          2213-2216
        }
}

• Leung, Lam
• Published 1 August 1995
• Physics
• Physical review. B, Condensed matter

We study the spin-1/2 Heisenberg antiferromagnet with an antiferromagnetic ${\mathit{J}}_{3}$ (third-nearest-neighbor) interaction on a square lattice. We numerically diagonalize this ``${\mathit{J}}_{1}$-${\mathit{J}}_{3}$'' model on clusters up to 32 sites and search for ground-state properties as the frustration parameter ${\mathit{J}}_{3}$/${\mathit{J}}_{1}$ changes. For ``larger'' ${\mathit{J}}_{3}$/${\mathit{J}}_{1}$ we find enhancement of the incommensurate spin order, in agreement with various theoretical predictions. But for intermediate ${\mathit{J}}_{3}$/${\mathit{J}}_{1}$, the low-lying excitation energy spectrum suggests that this incommensurate order is short range. Analysis of the ground-state expectation of the order parameter and the symmetries of the first excited state suggest that the spin-Peierls state is the best candidate for the ground state of the ${\mathit{J}}_{1}$-${\mathit{J}}_{3}$ model in an intermediate ${\mathit{J}}_{3}$/${\mathit{J}}_{1}$ region. \textcopyright{} 1996 The American Physical Society.