【摘要】 本文在ＶａｎＨｏｖｅ奇点模型下系统地研究了库仑作用对高温超导电性的影响，对超导转变温度Ｔｃ、绝对零度下能隙△（０）、同位素效应指数α和Ｔｃ处的比热跃变△Ｃ（Ｔｃ）作了解析和数值计算．结果表明，在ＶａｎＨｏｖｅ奇点模型下考虑库仑作用后，我们仍能得到高的Ｔｃ，并且能较好地解释同位素效应指数很小的实验结果．同时还表明在ＶａｎＨｏｖｅ奇点模型下考虑载流子局域性和巡游性的竞争对于解释高温超导体的实验结果也是很重要的．更多还原

【Abstract】 Abstract In this paper the influence of Coulomb repulsion to high--Tc superconductivity under the Van Hove singularity model is presented systematically. The analytical and numerical calculations of superconducting transition temerature (Tc), superconducting energy gap, isotope effect exponent(α)and the specific heat jump at Tc have been done. the results show that we can explain the isotope effect exponent of the high-Tc superconductor, which is generally smaller than the BCS value (α=1/2). Our results also show that the competition between the local and delocalized character of the carriers in the high-Tc superconductor is important in order to explain the experiments within the framework of the Van Hove singularity model.更多还原