Density matrix renormalization group study of critical behavior of thespin−12alternating Heisenberg chain

2002/12/11 by T. Papenbrock, T. Barnes, D. J. Dean +2
Physics and Astronomy · #Physics of Superconductivity and Magnetism #Quantum many-body systems #Theoretical and Computational Physics #cond-mat.stat-mech

paper · pdf · doi:10.1103/physrevb.68.024416

published as Phys. Rev. B 68, 024416 (2003) · 6 pages, 4 eps-figures

arxiv created 2002/12/11 · openalex publication_date 2003/07/28 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28

Abstract

We investigate the critical behavior of the S=1/2 alternating Heisenberg chain using the density matrix renormalization group. The ground-state energy per spin, e₀, and singlet-triplet energy gap \stackrel\ifmmode \else \~\fi\ensuremathΔ are determined for a range of alternations \ensuremathδ. Our results for the approach of e₀ to the uniform chain limit are well described by c\ensuremathδ^p, with p\ensuremath≈1.45. The singlet-triplet gap is also well described by a power law, with p\ensuremath≈0.73, half of the e₀ power. The renormalization group predictions of power laws with logarithmic corrections can also accurately describe our data provided that a surprisingly large-scale parameter \ensuremathδ₀ is present in the logarithms.

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