Speaker: AJ Leggett, 2003 Nobel laureate in physics
Title: Cuprate superconductivity without a`model'
Abstract: I start by reviewing the question: What can we reasonably say we know _for sure_ about superconductivity in the cuprates, without reliance on any microscopic "model"? Then I ask: On the basis of this knowledge and of some very generic and hopefully reasonable assumptions, are there interesting questions we can ask which we have some hope of answering definitively by experiment? I identify one such question, namely: In which regions of momentum and frequency space is the inter-conduction electron Coulomb interaction energy saved (or expended) when the system becomes superconducting? I conjecture a possible answer to this question, show that it is consistent with the dependence of the transition temperature on the c-axis layering structure and emphasize that it makes _quantitative and experimentally testable_ predictions.
Time(时间)：5月24日（星期五）14:00-15:30
Place(地点)：GJ104， 上大宝山校区
Inviter: Physics Department
报告人：安东尼 ⋅ 莱格特 （2003年物理学诺奖获得者）
题目：高温超导现象还没有理论
摘要：我从分析这样一个问题开始：在还没有可靠的微观理论的情况下，我们如何确定地断定高温超导体中的各类超导现象？ 我接着问，在这样的理解基础上，再加上一些原理性的、看上去很合理的假设，存不存在这样的一系列非常有意思的问题，实验可以让我们获取对它们的明确答案。其中的一个重要问题是这样的：超导态中的凝聚能是如何从电子的库伦相互作用获取的？我提出一个猜想，讨论它与现有实验结果的相容性，并会强调地指出它的一些列可被实验检验的预测。
邀请人：物理系
联系人：敖平教授
