Congratulations to Haiyuan Zou for successfully defending his PhD dissertation on "Tensor Renormalization Group Methods for Spin and Gauge Models."

"A very interesting feature of lattice spin and gauge models is that they do not suffer from the Dyson instability when the sign of the coupling g² is changed. Haiyuan’s thesis work explores the spin models in the complex g² plane, ways to improve their weak coupling expansions and possible constructions of their renormalization group flows. He found that the zeros of the partition function control the complex flows by acting as “gates”. This method is being used to understand the conformal window in four dimensional gauge theories. He developed accurate numerical methods based on the tensor renormalization group method to deal with the thermodynamics of the O(2) spin models and gauge theories. He studied the phase diagram of the O(2) model with a chemical potential and its connections with many-body models that can be implemented on optical lattices."
— Yannick Meurice, PhD advisor

Dr. Zou has accepted a position as a Postdoctoral Researcher in Prof. Vincent Liu’s group at the University of Pittsburgh.