Coexistence of superconductivity with partially filled stripes in the Hubbard model

报告摘要：Combining the complementary capabilities of two of the most powerful modern computational methods, we find superconductivity in both the electron- and hole-doped regimes of the two-dimensional Hubbard model (with next nearest neighbor hopping). In the electron-doped regime, superconductivity is weaker and is accompanied by antiferromagnetic Néel correlations at low doping. The strong superconductivity on the hole-doped side coexists with stripe order, which persists into the overdoped region with weaker hole density modulation. These stripe orders, neither filled as in the pure Hubbard model (no next nearest neighbor hopping) nor half-filled as seen in previous state-of-the-art calculations, vary in fillings between 0.6 and 0.8. The resolution of the tiny energy scales separating competing orders requires exceedingly high accuracy combined with averaging and extrapolating with a wide range of system sizes and boundary conditions. These results validate the applicability of this iconic model for describing cuprate high-Tc superconductivity.
报告人简介：秦明普于2008年本科毕业于北京航空航天大学。2013年在中国科学院物理研究所获得理学博士学位。之后在美国威廉玛丽学院从事博士后工作，2014 年至2018年同时加入Simons基金会多电子问题合作组。2019年1月加入上海交通大学物理与天文学院任长聘教轨副教授。主要研究凝聚态物理中的强关联量子多体问题。致力于发展和改进精确的强关联多体方法，包括密度矩阵重整化群，辅助场量子蒙特卡洛，张量网络态等方法。在费米子负符号问题和密度矩阵重整化群的推广方面中做出了一些工作。最近重点关注二维Hubbard 模型基态的求解，与合作者发现二维纯Hubbard模型的基态为条纹相，没有超导序；有次近邻跃迁的Hubbard模型的基态与铜基超导能定性吻合。