Quantum spin chains: some numerical and analytical studies

Author(s)

Gilberto Medeiros Nakamura

• Document type: Master's Dissertation
• Press: São Carlos.
• Institution: Universidade de São Paulo (USP). Instituto de Física de São Carlos (IFSC/BT)
• Defense date: 2006-03-09

Examining board members

Francisco Castilho Alcaraz; Evaldo Mendonca Fleury Curado; Raimundo Rocha dos Santos

• Advisor: Francisco Castilho Alcaraz

Abstract

In this dissertation, we have studied exactly integrable unidimensional quantum spin chains of spin 1/2 and spin 1. Special atention was given to the properties of the energy eigenspectra of these chains and particularly to their finite size effects. To achieve this goal, we have explored the invariance by conformal transformations of the models in their critical points. As an appreciation of these studies, we have studied the exactly integrable model NDF of spin 1, proposed by Alcaraz e Bariev. We verified that such model possess a quantum phase transition. (AU)