Density Matrix Renormalization Group Study of the Enhanced Hole-Hopping Model of High Temperature Superconductivity

Abstract

<p>The thermodynamic behaviour of the enhanced hole-hopping model of high temperature superconductivity is investigated using the numerical Density Renormalization Group (DMRG) technique. The enhanced hole-hopping or Δt model is a Hubbard-like lattice model that has been proposed to account for superconductivity in the high temperature superconducting materials. Extensive results for this model have been obtained by others within the BCS approximation. This thesis does not attempt to motivate the use of the Δt model but rather it is the goal of this work to characterize the accuracy of two techniques used to study this model. In particular, the ground state energy and binding energy for a pair of particles as calculated within the DMRG are compared to similar results obtained from BCS and Exact Diagonalization studies. The DMRG is a relatively new numerical technique and consequently a detailed discussion of its implementation is given. Application of the DMRG necessarily confines investigation to one dimension. Analysis of finite size effects is also presented where warranted.</p>