Among the quantum integrable models, there is a special class which possesses nontrivial topological structure. These models play important benchmark roles to understand topological phenomena in many-body physics but had resisted solutions for several decades. In this talk, I will introduce a recently developed analytic theory-off-diagonal Bethe ansatz, which provides a universal method to solve this long-standing problem. As examples, I will show how the Majorana fermions can be generated in the quantum Moebius strip and how the spionon excitations behave in a spin chain with non-diagonal boundaries.

Yupeng Wang got his BS degree from department of optics, Shandong University in 1984 and his PhD from institute of physics of CAS in 1994. He became a full professor in Institute of Physics in 2000; He was the deputy director of the institute from 2003-2007 and  director from 2007-1017. From 2012, he has been the vice president of Chinese Physical Society. His research interest mainly focuses on low-dimensional many-body systems. Especially, his contribution to the universal theory of  quantum integrable systems has been highly recognized. Awards: Second class  National Award for Natural Science of China in 2012; Qiushi Award in 1998, Ye Qisun Physics Award of CPS in 2005.