文档介绍:关键词:铁基超导体; Minimum 模型:正1-波;扩展 s-波
Abstract
Copper oxide high-temperature superconducting material has been discovered 1l10re than 20 years. Today ,people still could not explain High-temperature superconductivity mechanism. This has restrained the development of superconducting technology to some extent. [n additio口, the copper oxide supercondllctors are crisp and are diftìcult to tàbricate ,this prevent its
large-scale applications in indllstry. So, people have been exploring a ne飞v kind of
high-temperature superconducting material outside the copper-based high-temperature superconducting materials that cal1 e the deficiencies of copper oxicle high-temperature
superconductors ,to stlldy the supercondllctivity phenomenon with a point of view. The discovery
of iron-based superconductors in 2008 brings about the new opportunity,a new round study of high-tcmpcraturc supcrconductors has sprcad worldwidc quickly.
In order to describe the basic propeliies of iron-based superconductors , we use a
Single-band Minimu l11 moclel based 011 the t-J -J
1 2
model il1 this paper,paratively
study the basic properties of d -wave and thc l- s -wavc superconductors.
Thc main contents ofthc thcsis are as follows.
First ,we describe the development histOlγof superconductors ancl the relevant theoretical models ,especially the Singlc-band Minimum !11odcl ,for iron-bascd supcrconductors ,ments have .
Second ,we discuss the basic properties of iron-based superconductors by the Single-bancl Minimu I11 mocle l. With Fortran program ,we calculate order parameters as a function of tcmpcraturc ,ordcr paramctcrs as a 且mction of thc rcnormalizcd parumctcr t ,thc impact of c10ping 011 the superconducting ,ordcr paramcters and crgy as a fU l1ction of J二. The obtained results show that ,the relationship between the superconducting order parameters and
temperature is BCS like. For the used parameter 飞 the d1 phase of extended- s -wave is very weak all the time,in the high temperatur