学术报告（11月16日 周五 下午14:30-16:00）

主持人：叶鹏 教授

欢迎广大师生前来参与！

【摘要】

Topological qauntum field theory(TQFT) is a very powerful theoretical tool to study topological phases and phase transitions. In 2 + 1D, it is well known that the Chern-Simons theory captures all the universal topological data of topological phases, e.g., quasi-particle braiding statistics, chiral central charge and even provides us a deep insight for the nature of topological phase transitions. Recently, topological phases of quantum matter are also intensively studied in 3 + 1D and it has been shown that loop like excitation obeys the so-called three-loop-braiding statistics. In this talk, I will discuss a TQFT framework to understand the quantum statistics of loop like excitation in 3 + 1D. Most surprisingly, this new class of 3+1D TQFT even provides us a new route towards a quantum theory of gravity.

【报告人简介】

Education:

1. Ph.D., Physics, 2003-2007, Center for Advanced Study, Tsinghua University
2. Bachelor, Fundamental Science (Mathematics and Physics), 1999-2003, Tsinghua University

Position:

1. Since 03/2016, Associate Professor, Department of Physics, The Chinese University of Hong Kong
2. Adjunct Professor, 2015-2020, University of Waterloo
3. Director's Fellow, 2012-2016, Perimeter Institute (IQIM Fellow 2012-2013, Caltech)
4. Associate Specialist, 2009-2012, Kavli Institute for Theoretical Physics, UCSB
5. Postdoctoral Fellow, 2007-2009, MIT

Research Interests:

1. Entanglement renormalization and deep learning.
2. Classification of topological phases in interacting bosonic and fermionic systems.
3. Tensor network simulation for two dimensional strongly correlated systems, e.g., frustrated magnets and Hubbard model.
4. Unification of mass mixing phenomena in quark and lepton sectors. Predictions on leptonic CP violation angle and absolute neutrino mass.
5. Topological aspects of fundamental particles and unification of three generations.
6. Super topological quantum field theory and quantum gravity.

Selected Recent Publications:

1. Z.-C. Gu and Xiao-Gang Wen, "Symmetry-protected topological orders for interacting fermions - fermionic topological non-linear sigma-models and a group super-cohomology theory", Phys. Rev. B 90, 115141 (2014).
2. Xie Chen, Z.-C. Gu, Zheng-Xin Liu, Xiao-Gang Wen, "Symmetry protected topological orders in interacting bosonic systems", Science 338, 1604 (2012).
3. Michael Levin and Z.-C. Gu, "Braiding statistic approach to symmetry-protected topological order", Phys. Rev. B 86, 115109 (2012).
4. K. Sun, Z.-C. Gu, H. Katsura and S. Das Sarma, "Nearly flat bands with nontrivial topology", Phys. Rev. Lett. 106, 236803 (2011).

Xie Chen, Z.-C. Gu and Xiao-Gang Wen, "Classification of gapped symmetric phases in 1D spin systems", Phys. Rev. B 83, 035107 (2011).