Effects of aperiodicity on quantum spin chains

• Grant number: 10/11356-2
• Support Opportunities: Regular Research Grants
• Start date: November 01, 2010
• End date: October 31, 2012
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Andre de Pinho Vieira
• Grantee: Andre de Pinho Vieira
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

We aim at studying effects of deterministic aperiodicity on the lowtemperature properties of spin-1 Heisenberg chains and on the quantum phase transitions of XY spin-1/2 chains. Our approach makes use of extensions of the Ma-Dasgupta-Hu real-space renormalizationgroup technique, supplemented by numerical calculations based on quantum Monte Carlo and free-fermion methods, in order to determine properties such as specific heat, magnetic susceptibility and field induced magnetization, as well as critical exponents associated with phase transitions, verifying and extending results in the literature. (AU)