Statistical mechanics is one of the main research directions of Yang Zhenning. His characteristic in statistical mechanics is to strictly solve and analyze the general model rooted in physical reality, so as to grasp the essence and essence of the problem. From 65438 to 0952, Yang Zhenning and his collaborators published three important papers on phase transition.
For the many-body problem of bosons, Yang Zhenning and his collaborators published or completed a series of papers on thin boson many-body systems around 1957. First, he co-published two papers with Huang, and applied the pseudopotential method to this field. After writing a paper on parity conservation in weak interaction and waiting for the experimental results, Yang Zhenning and Li Zhengdao first got the correct ground state energy correction by double collision method.
The 1 dimensional fermion problem discussed by Yang Zhenning is very important in the experimental study of cold atoms. The nested Bethe hypothesis method he invented in this paper was used by Lieb and Wu Fayue to solve the 1 dimensional Hubbard model the following year. Hubbard model later became the basis of many theoretical studies on high temperature superconductivity.
Yang Zhenning and Yang Zhenping pushed the boson problem in the repulsive potential of 1 dimensional δ function to a finite temperature. This is the first time in history that a quantum statistical model of interaction is obtained at a finite temperature (T >). This model and results were later realized and verified by experiments in the cold atomic system.