Effect of Weak Inhomogeneities in High Temperature Superconductivity

 
 
 
 

Effect of Weak Inhomogeneities in High Temperature Superconductivity

Show full item record


Title: Effect of Weak Inhomogeneities in High Temperature Superconductivity
Author: Doluweera, D. G. Sumith Pradeepa
Description: We present results of three studies done using a dynamical cluster quantum Monte Carlo approximation. First, we investigate the d-wave superconducting transition temperature Tc in the doped 2D repulsive Hubbard model with a weak inhomogeneity in hopping in the form of checkerboard pattern or a lattice of 2×2 plaquettes. Near neighbor hoppings within a plaquette is t and that of between the plaquettes is t'. We investigate Tc in the weak inhomogeneous limit 0.8t < t'< 1.2t. We find inhomogeneity (t'≠ t) suppresses Tc. The characteristic spin excitation energy (effective exchange energy) and the strength of d-wave pairing interaction decrease with decreasing Tc. The latter observations suggest a strong correlation among effective exchange interaction, Tc and the d-wave pairing interaction of the system. Second*, we further find that enhancement of effective exchange interaction causes a slight increase in Tc of a weakly disordered system with low impurity concentration, compared to the homogeneous system. Here the disorder is introduced to homogeneous repulsive 2D Hubbard model as a weak local potential disorder. Third, we present an improved maximum entropy method to analytically continue quantum Monte Carlo data with a severe sign problem. * A result from a collaborative study done with A. Kemper of Florida State University.
Permanent Link: http://rave.ohiolink.edu/etdc/view?acc_num=ucin1227215152
http://hdl.handle.net/2374.OX/105960
Date: 2008

Files in this item

Files Size Format View

There are no files associated with this item.

This item appears in the following Collection(s)

Show full item record