报告摘要：We present exact solutions of repulsive SU(N) Hubbard models in lattices with flat band. We prove the SU(N) Hubbard model can be mapped to a classical percolation problem for all lattices with flat-band in arbitrary dimensions, provided the quasi-locality and local-connectivity conditions are satisfied. We then consider 1D and 2D Tasaki lattices as examples and solve for the para-ferro magnetic phase transition points. We also rigorously prove the existence of ferromagnetic state for arbitrary values of N and dimensionalities if the single-particle flat-band is 1/N filled. Our work provides a starting point and benchmark for future analysis on SU(N) systems.
报告人简介：张威, 2006年美国佐治亚理工学院物理系博士毕业，之后在密歇根大学做博后。08年起加入中国人民大学，现在是物理系教授, 中国人民大学教务处副处长。主要从事原子分子物理和量子信息领域的理论研究, 在国际期刊发表学术论文60 余篇, 出版英文教材和专著 3 部, 翻译出版多部科普作品。先后入选教育部新世纪优秀人才、北京市科技新星、国家自然科学基金委优秀青年科学基金、教育部长江学者奖励计划青年学者等人才计划。