（上海科技大学）

摘 要：

The Hubbard model plays a paradigmatic role in the theory of strongly correlated many-body systems. It is believed by many to be the simplest possible model for producing both antiferromagnetic ordering and d-wave superconductivity (SC), depending on doping. However, growing numerical studies suggest that the simplest repulsive Hubbard model in doping range relevant for hole-doped cuprates exhibits short-range d-wave SC in the ground state. It is natural to ask what more is needed beyond the simplest Hubbard model with strong U in order to realize d-wave SC. In this talk, we will discuss three possible microscopic terms which could induce the d-wave SC: the next-nearest-neighbor hopping, the nearest-neighbor density attraction, and the Su-Schrieffer-Heeger electron phonon coupling. Using large-scale density matrix renormalization group simulations, we explore the quantum phase diagram produced by the additional coupling terms and Hubbard interaction on long square cylinders. The numerical evidence and physical properties of the d-wave SC phases induced by the three coupling terms will be discussed in detail. 

报告人简介：

蒋易凡研究员2017年毕业于清华大学高等研究院并获博士学位，导师为姚宏教授。2017-2020年，他在斯坦福直线加速中心(SLAC)开展博士后研究工作，导师是Thomas P. Devereaux教授与姜红臣研究员。2021年蒋易凡加入上海科技大学物质学院，近年来主要的研究方向是强关联电子体系的理论与数值模拟。

邀请人：李自翔（82649331）