Chen Ning Yang

Chen-Ning Franklin Yang
Born	1 October 1922 (1922-10-01) (age 87) Hefei, Anhui, China.
Residence	China
Nationality	China, United States
Fields	Physics
Institutions	Institute for Advanced Study State University of New York at Stony Brook Chinese University of Hong Kong Tsinghua University University of Chicago
Alma mater	National Southwestern Associated University Tsinghua
Doctoral advisor	Edward Teller
Notable awards	Nobel Prize in Physics (1957) Rumford Prize (1980) National Medal of Science (1986) Benjamin Franklin Medal (1993) Albert Einstein Medal (1995)

Chen-Ning Franklin Yang (traditional Chinese: 楊振寧; simplified Chinese: 杨振宁; pinyin: Yáng Zhènníng) (born October 1, 1922^[1]) is a Chinese-born American physicist who worked on statistical mechanics and particle physics. He, together with Tsung-Dao Lee, received the 1957 Nobel prize in physics for their work on parity nonconservation of weak interaction.

Biography

Yang was born in 1922 in Hefei, Anhui, China, his father Yang Ko-Chuen (traditional Chinese: 杨武之; pinyin: Yáng Wǔzhī) (1896-1973) was a mathematician and his mother Luó Mènghuà (罗孟华) was a housewife. Yang attended elementary school and high school in Beijing, in the Autumn of 1937 his family moved to Hefei after Japanese invaded China in full scale, in 1938 they moved to Kunming, Yunnan where the National Southwestern Associated University was located. In the same year, as a second year student, Yang passed the entrance examination and studied in National Southwestern Associated University. He received bachelor's degree in 1942, the thesis was about application of group theory to molecular spectra, under the supervision of Wu Ta-You (吴大猷) (1907-2000). He continued to study graduate courses there for two years under the supervision of Wang Zhuxi (王竹溪) (1911～1983) working on statistical mechanics, in 1944 he received his master's degree. In the same year Yang achieved a special support funding between China and America (庚子赔款, known as Boxer Indemnity, restitution of part of war compensation of Eight-Country United Armies' Aggression in China) to study in America. But he was delayed for one year, during which time he taught in a middle school as a teacher and studied field theory.

From 1946, Yang studied in The University of Chicago with Edward Teller (1908-2003), where he received his doctorate in 1948 and remained for a year as assistant to Enrico Fermi. In 1949 he moved to the Institute for Advanced Study where he began a period of fruitful collaboration with T. D. Lee Tsung-Dao Lee. In 1966 he moved to the State University of New York at Stony Brook and became the Albert Einstein Professor of Physics and the first director of a newly founded Institute for Theoretical Physics which is now known as C. N. Yang Institute for Theoretical Physics. He retired from Stony Brook in 1999 as Emeritus Professor.

He has been elected a Fellow of the American Physical Society, the Chinese Academy of Sciences (中国科学院, Beijing ), the Academia Sinica (中央研究院, Taiwan), the Russian Academy of Sciences, the Royal Society, etc. and was awarded an honorary doctorate by Princeton University (1958), Moscow State University (1992), Chinese University of Hong Kong (1997), etc.

Yang visited the Chinese mainland in 1971 for the first time after the thaw in China-US relations, and has subsequently made great efforts to help the Chinese physics community to rebuild research atmosphere which was destroyed by the radical political movements. After retiring from Stony Brook he returned as honorary director of Tsinghua University, Beijing, where he is the Huang Jibei - Lu Kaiqun professor at the Center for Advanced Study (CASTU).

Yang married Chih-li Tu (traditional Chinese: 杜致禮; pinyin: Dù Zhìlǐ), a teacher, in 1950 and has two sons and a daughter: Franklin Jr., Gilbert, and Eulee (in order of age). His father-in-law was the Kuomintang General Du Yuming. His wife died in the winter of 2003. At the age of 82, Yang became engaged to 28-year old Weng Fan (simplified Chinese: 翁帆; pinyin: Wēng Fān) who was studying for her master's degree at Guangdong University of Foreign Studies. They married in early 2005.

Academic achievements

Yang has worked on statistical mechanics, condensed matter theory, particle physics and quantum field theory.

In The University of Chicago, Yang first spent twenty months working in an accelerator lab, but he later found he was not as good as an experimentalist and switched back to theory. His doctoral thesis was about anglular distribution in nucleon reactions. Later he worked on particle phenomenology; a well known work was the Fermi-Yang model treating Pion meson as a bound nucleon-antinucleon pair. In 1956, he and T.D. Lee Tsung-Dao Lee proposed that in the weak interaction the parity symmetry was not conserved, Chien-Shiung Wu's team at the National Bureau of Standards in Washington experimentally verified the theory. Yang and Lee received the 1957 Nobel Prize in Physics for their parity violation theory. Yang has also worked on neutrino theory(with T.D.Lee, 1957, 1959), CT nonconservation(with T.D.Lee and R.Oheme, 1957), electromagnetic interaction of vector mesons(with T.D.Lee, 1962), CP nonconservation(with Wu Tai-Tsun, 1964). It is well known that T. D. Lee fell out with Yang in 1962. Please refer to T.D Lee's publication in 2005 titled "Response to the Dispute of Discovery of Parity Violation" in Chinese ISBN 7542409298 (electronic download available online from T.D. Lee's homepage).

Yang is also well known for his collaboration with Robert Mills in developing non Abelian gauge theory, widely known as the Yang-Mills theory. Such "Yang-Mills theories" are now a fundamental part of the Standard Model of particle physics. In the 1970s Yang worked on the topological properties of gauge theory, collaborating with Wu Tai-Tsun to elucidate the Wu-Yang monopole. Unlike the Dirac monopole, it has no singular Dirac string.

Yang has had a great interest in statistical mechanics since his undergraduate era, in the 1950s and 1960s, collaborated with Tsung-Dao Lee and Kerson Huang, etc. he studied statistical mechanics and condensed matter theory. He studied theory of phase transition and elucidated the Lee-Yang circle theorem, properties of quantum boson liquid, two dimensional Ising model, flux quantization in superconductors(with N. Byers, 1961), and proposed the concept of Off-Diagonal Long-Range Order(ODLRO, 1962). In 1967, he found a consistent condition for a one dimensional factorized scattering many body system, the equation was later named the Yang-Baxter equation, it plays an important role in integrable models and has influenced several branches of physics and mathematics.

Awards

• Nobel Prize in Physics (1957)
• Rumford Prize (1980)
• National Medal of Science (1986)
• Benjamin Franklin Medal (1993)
• Bower Award (1994)
• Albert Einstein Medal (1995)
• N. Bogoliubov Prize (1996)
• Lars Onsager Prize (1999)
• King Faisal International Prize (2001)

See also

• Parity violation
• Yang-Mills Theory
• Yang-Baxter equation
• Yangian
• Lee–Yang theorem
• Wu-Yang monopole

Notes

References

• Yang, C.N. (1952) [1952]. Special problems of statistical mechanics. Seattle: University of Washington Press. ASIN B0007FZHH4. 
• Yang, C.N. (1963) [1961]. Elementary Particles: A Short History of Some Discoveries in Atomic Physics. Princeton: Princeton University Press. ASIN B000E1CBGG. 
• Yang, C.N. (1983) [1983]. Selected papers 1945-1980, with commentary (Chen Ning Yang). San Francisco: W.H. Freeman. ISBN 071671406X. 
• "C.N. Yang Institute for Theoretical Physics (YITP)". Retrieved on 2008-01-05.

External links

• Nobel biography
• YITP website (The C. N. Yang Institute for Theoretical Physics at the State University of New York at Stony Brook)
• Past Faculty biography (Institute for Advanced Study)
• Symmetries and Reflections (C.N. Yang retirement symposium at the State University of New York at Stony Brook)
• Official homepage I (State University of New York at Stony Brook)
• Official homepage II (The Chinese University of Hong Kong)