Title: A brief review of the recent progresses in the study of the cuprate superconductivity
Speaker: Prof. Tao Li, Renmin University
Time: Dec. 24 (Friday), 10:00 pm
Place: Rm M830, IOP-CAS
Abstract: There is now strong evidence that the strange metal behavior of the hole-doped high-Tc cuprates is induced by the quantum critical fluctuation around the pseudogap end point, where the Fermi surface changes its topology from hole-like to electron-like. However, experiments show that the quantum critical behavior in the high-Tc cuprates is qualitatively different from that observed in the heavy Fermion systems and the iron-based superconductors, in both of which the quantum critical behavior can be attributed to the quantum phase transition toward a symmetry breaking phase. The fact that the pseudogap exists as a spectral gap without a corresponding symmetry breaking order, together with the fact that the strange metal behavior occurs as a quantum critical behavior without a corresponding symmetry breaking phase transition, exposes the central difficulty of the field: the lack of a universal low energy effective theory description of the high-Tc phenomenology beyond the Landau paradigm. Recent experiments imply that the dualism between the local moment and the itinerant quasiparticle character of the electron in the high-Tc cuprates may serve as an organizing principle to go beyond the Landau paradigm and may hold the key to the mystery of the pseudogap phenomena and the strange metal behavior. In this short review, we summarize the recent progresses in the study of the cuprate superconductivity made possible by the tremendous efforts devoted during the last 15 years. Here we will focus on drawing the implications of these recent progresses on the construction of a coherent picture for the high-Tc problem, rather than providing a thorough review of the experimental literatures, which has been done in many excellent review articles on related topics.
About the speaker: 李涛教授，1996年在中国科技大学物理系获得凝聚态物理本科和硕士学位，1999年在北京大学物理系获得凝聚态物理博士学位。1999年至2005年在清华大学高等研究中心从事研究工作，从2005年起为中国人民大学物理系教授。主要研究领域为强关联电子体系的基础理论研究，重点关注高温超导微观机理和量子磁性理论研究。在高温超导的共振价键理论和量子自旋液体的理论研究和数值模拟方法方面取得一系列成果。