Yang Zhenning was born in Sanhe Town, Hefei (now Feixi County). At the age of 4, his mother began to teach Yang Zhenning to read. In 1 years, Yang Zhenning learned 3000 words. He is a professor at the Institute of Advanced Studies of Tsinghua University and the Chinese University of Hong Kong. He is also an academician of China Academy of Sciences, American Academy of Sciences, Academia Sinica, Russian Academy of Sciences, Catholic Academy of Sciences, Brazilian Academy of Sciences, Venezuelan Academy of Sciences, Spanish Academy of Sciences and Royal Society of England.
1949, the first composite model of elementary particles was put forward in cooperation with Enrico Fermi. 1956 cooperated with Li Zhengdao to put forward the theory of parity non-conservation of weak interaction, and * * * won the 1957 Nobel Prize in Physics. 1997 The Purple Mountain Observatory named an asteroid with an international number of 342 1 as "Yang Zhenning Star".
In 1954, Yang Zhenning and Mills put forward a theoretical structure called non-Abelian gauge field.
1956, Yang Zhenning and Li Zhengdao published an article, which overthrew a central message of physics-parity conservation elementary particles are exactly the same as their mirror images.
2065438+In February 2007, Yang Zhenning, a former foreign academician of China Academy of Sciences, gave up his foreign nationality, joined China nationality and was officially transferred to China Academy of Sciences. 2018 April 16 was elected honorary chairman of the board of trustees of West Lake University.
Secondly, Yang Zhenning is the third "all-rounder in physics" in the 20th century after Einstein and Fermi, and he is one of the most famous scientists in China. Saos, an experimental physicist, is the director of Brookhaven National Laboratory. He said, "Yang Zhenning is a man with a great mathematical mind. However, due to his early education, he was very interested in the details of the experiment.
People praised Yang Zhenning, the Nobel Prize winner who spent half a century at the forefront of theoretical physics, as a scientist with perseverance and mathematical genius. He devoted himself to revealing the symmetry of nature, which is often hidden behind the chaotic experimental physical results.
Yang Zhenning has long been committed to the cross-study of physics and mathematics. In this field, a set of beautiful equations can be a source of inspiration, and even insight into how the physical world works before there is experimental evidence. This is a world that is difficult for laymen to understand. There are equations filled with Greek letters on the blackboard, "taste" and "style" seek to solve problems with mathematics, and inner inspiration seeks to describe the material world with correct language.
academic achievement
1, phase transition theory
Statistical mechanics is one of the main research directions of Yang Zhenning. His characteristic in statistical mechanics is to solve and analyze the general model rooted in physical reality strictly, so as to grasp the essence and essence of the problem beautifully. From 65438 to 0952, Yang Zhenning and his collaborators published three important papers on phase transition. The first paper is about the spontaneous magnetization of two-dimensional Ising model, which he independently completed the year before last, and obtained the critical exponent of 1/8. This is the longest calculation that Yang Zhenning has ever done. Ising model is the most basic but extremely important model in statistical mechanics, but its importance in theoretical physics was not widely recognized until 1960s. 1952, Yang Zhenning also cooperated with Li Zhengdao to complete and publish two papers on phase transition theory. Two articles were submitted and published at the same time, which aroused Einstein's interest. In this paper, the analytic properties of giant partition function are studied by analytic continuation method, and it is found that the distribution of its roots determines the state equation and phase transition properties, which eliminates the suspicion that different thermodynamic phases can exist under the same interaction. The climax of these two papers is the unit circle theorem in the second paper, which points out that the zero point of the giant partition function of the lattice gas model attracting interaction lies on the unit circle on the complex plane. In statistical mechanics and field theory, this theoretical masterpiece is like a small and exquisite shell, and its charm is undiminished.
2. Boson many-body problem
Out of his interest in liquid helium superfluid, Yang Zhenning published or completed a series of papers on thin boson multibody systems with his collaborators around 1957. First, he published two papers with Huang and Luttinger, and applied the pseudopotential method to this field. After writing the article "Is parity conserved in weak interaction", while waiting for the experimental results, the correct ground state energy correction was obtained by the double collision method, and then the same results were obtained by the pseudo-potential method. The most surprising energy correction they got was the famous square root correction term, but it could not be verified by experiments at that time. To their surprise, in recent years, with the development of cold atomic physics, this correction term has been confirmed by experiments.
3. Young-Baxter equation
In 1960s, Yang Zhenning found the strict solution of quantum statistical model by trying to find off-diagonal long program model. 1967, it was found that the fermion quantum many-body problem in the repulsive potential of 1 dimensional δ function could be transformed into a matrix equation, which was later called Yang-Baxter equation (because Baxter also found this equation in another problem of 1972). In 1967, Yang Zhenning also wrote an article published in the following year, further discussing the problem of S matrix. Later, it was found that Young-Baxter equation is an extremely important equation in mathematics and physics, which is closely related to kink theory, braid group, Hopf algebra and even string theory. The 1 dimensional fermion problem discussed by Yang Zhenning is very important in the experimental study of cold atoms in recent years, and 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.
4. Parity is not conserved in weak interaction.
Symmetry is an important embodiment of the beauty of physics, and it is also one of the themes of theoretical physics in the 20th century. From classical physics and crystal structure to quantum mechanics and particle physics, symmetry analysis is a powerful tool in physics. Yang Zhenning's many contributions to particle physics show that he is good at symmetry analysis. He can often use symmetry accurately, get results quickly with elegant methods, and highlight the essence and ingenuity. 1999, Yang Zhenning was called "the king of symmetry" at an academic conference in Brook, Si Tong.
5. From 65438 to 0950, Yang Zhenning's paper on p0 decay and his paper with Tiomno on phase factor in β decay established his leading position in this field. 1956, the mystery of θ-τ is the most important problem in particle physics. At that time, there was a general discussion about whether parity could not be conserved. Yang Zhenning and Li Zhengdao moved from the specific physical problem of θ-τ to a more general problem, and put forward the possibility that parity is conserved in strong interaction and electromagnetic interaction, but not necessarily in weak interaction, separating the decay process dominated by weak interaction. Then, through concrete calculation, it is found that there is no experiment to prove whether parity is conserved under weak interaction. They also pointed out several key weak interaction experiments to test whether parity is conserved in weak interaction. 1in the summer of 956, Wu Jianxiong decided to do one of several experiments they pointed out about the decay of 60Co β. In June, 5438+the following year 10, the experimental group led by him proved that parity is indeed not conserved in weak interaction, which caused great shock in the whole physics field. Because of this work, Yang Zhenning and Li Zhengdao won the 1957 Nobel Prize in Physics.
6. Three discrete symmetries: time reversal, charge yoke and parity.
In August 1956, Oehme sent a letter to Yang Zhenning, questioning the conservation of parity in weak interaction, proposing the relationship among three discrete symmetries: parity (P), charge yoke (C) and time reversal (T). This led Yang Zhenning, Li Zhengdao and Hermite to publish a paper 57e to discuss the relationship between the non-conservation of P, C and T respectively. This paper plays a decisive role in the theoretical analysis of CP non-conservation in 1964.
7. Theoretical discussion of high-energy neutrino experiment.
1960, in order to get more information about weak interaction experiments, Li Zhengdao and Yang Zhenning discussed the importance of high-energy neutrino experiments in theory by using the ideas of experimental physicist Schwartz. This is the first theoretical analysis of neutrino experiment, which leads to many important research work later.
8. Phenomenological framework of 8.CP non-conservation
1964 found that CP is not conserved, which led many articles to guess its root cause. Yang Zhenning and Wu Dajun ignored the theoretical speculations that were divorced from reality, but made a phenomenological analysis of the non-conservation phenomenon of CP, and established a phenomenological framework for the later analysis of such phenomena. This reflects Yang Zhenning's down-to-earth style and clearly shows that he is influenced by Fermi.