2003/12/22 by Nicolas Laflorencie, Nicolas laflorencie, Heiko Rieger +2 · 3 citations
Mathematics · Physics and Astronomy · #Correlation function (quantum field theory) #Exponent #Mathematical physics #Mathematics #Physics #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Quantum mechanics #Randomness #Renormalization group #Series (stratigraphy) #Spin (aerodynamics) #Spin glass #Statistical physics #Statistics #Theoretical and Computational Physics #Thermodynamics #cond-mat.dis-nn #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.70.054430
published as Phys. Rev. B 70, 054430 (2004) · 13 pages, 15 figures, submitted to Phys. Rev. B
arxiv created 2003/12/22 · openalex publication_date 2004/08/31 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The random antiferromagnetic spin-1∕2 XX and XXZ chain is studied numerically for varying strength of the disorder, using exact diagonalization and stochastic series expansion methods. The spin-spin correlation function as well as the stiffness display a clear crossover from the pure behavior (no disorder) to the infinite randomness fixed point or random singlet behavior predicted by the real space renormalization group. The crossover length scale is shown to diverge as \ensuremathξ\ensuremath∼D^\ensuremath-\ensuremathγ, where D is the variance of the random bonds. Our estimates for the exponent \ensuremathγ agrees well within the error bars with the one for the localization length exponent emerging within an analytical bosonization calculation. Exact diagonalization and stochastic series expansion results for the string correlation function are also presented.