[超导基础理论和实验技术系列讲座（六十四）] Can high-temperature superconductivity be an entirely different beast within our reach?
High-temperature superconductivity in the cuprates has been discovered for three decades and yet consensus of a reasonable description of its true nature has not been reached. One major roadblock is the strongly correlated normal state for which no “small parameter” is known to connect it to a well-understood state. This talk will first cover the basic concept of emergent physical effects in quantum many-body systems, using the cuprates as good examples. It will then propose an unconventional approach to the hard problem of high-Tc superconductivity by exploring the emerged strong binding limit. This lead to a consistent picture that account for a wide range of observed phenomena.
Specifically, it indicates that the superconducting gap observed in the quasi-particle spectra of ARPES and STS measurement can be quantitatively described by a second kind of superconducting gap driven by kinetic energy, instead of the pairing strength-controlled Bogoliubov gap. Furthermore, the nature of the quantum critical point at 5% doping and the weakened short-range superconducting correlation nearby can be understood from the divergence of the effective mass of the pre-formed pairs. Most amazingly, all these quantitative agreements are obtained without any adjustable parameters other than the normal-state dispersion measured by ARPES, strongly supporting the validity of the novel approach to the properties of high-Tc superconductivity in the cuprates, and perhaps in other unconventional superconductivity observed in other strongly correlated systems.
Wei Ku, Zhiyuan Chaired Professor in Department of Physics and Astronomy, Shanghai Jiao Tong University. After receiving his PhD degree in year 2000 from University of Tennessee at Knoxville, Professor Wei Ku worked as a postdoctoral researcher in University of California at Davis for 2.5 year. He then joined Brookhaven National Laboratory in year 2003 as a staff scientist and serve as an adjunct professor in Stony Brook University in New York. In year 2016, he accepted a Zhiyuan chaired professor position and relocated to Shanghai Jiao Tong University in China under the government’s Qianren project. Professor Ku’s research interest includes strongly correlated physics in real materials, high-temperature superconductivity, spin/orbital correlation in correlated materials, effects of disordered impurities, and electronic excitations.
联系人：朱北沂 / 8264-9927