Author Description

This dissertation, "Theoretical Study of Inhomogeneous Properties in Unconventional Superconductors" by Lei, Jiang,, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled THEORETICAL STUDY OF INHOMOGENEOUS PROPERTIES IN UNCONVENTIONAL SUPERCONDUCTORS submitted by Jiang Lei for the Degree of Master of Philosophy at The University of Hong Kong in August 2005 Recent observations support the existence of inhomogeneous electronic phase in high-temperature superconducting cuprates. Due to the competition among ordered states, intrinsic inhomogeneity is believed to be one of the fundamen- tal aspects of strongly correlated system. More specically, very recent high- resolution scanning tunneling microscopy (STM) experiments on cuprate su- perconductors such as NCCOC and BSCCO reveal ambiguous evidence of real- space modulation of local density of states (LDOS) spectrum at low energies in the pseudogap state and superconducting state. Motivated by these experimen- tal ndings, a phenomenological study of electronic structure was conducted bysolving the Bogoliubov-de Gennes equations based upon the assumption of the existence of superconducting order or charge density modulations. Numerical results for some physical quantities such as LDOS, spectral weights and the spin susceptibility were presented. Some interesting features of experimental measurements were reproduced in the calculations. Detailed comparisons with experiments have also been made. On the other hand, the extrinsic inhomogeneity, such as impurities or struc- ture defects, may suppress the superconducting order and provide a prob