Physical review. B, Condensed matter
Finite-size study of a spin-1/2 Heisenberg chain with competing interactions: Phase diagram and critical behavior
K. Hallberg, Eduardo R. Gagliano, C. A. Balseiro
Abstract
We study the ground-state properties of the one-dimensional anisotropic spin-1/2 antiferromagnetic Heisenberg model with competing antiferromagnetic second-neighbor Ising interaction. Using the modified Lanczos method, we obtain the phase diagram in parameter space and different correlation functions, which we use to characterize the different phases. For small next-nearest-neighbor parameters we evaluate the critical exponent \ensuremath{\eta} of the spin-spin correlation function. We find good agreement between the numerical results and those obtained using the Luther and Peschel approach.