Leroy Chang
Taiwanese–American solid-state physicist (1936–2008)

Leroy Chang
張立綱
Born
Leroy Li-Gong Chang

(1936-01-20)January 20, 1936
Kaifeng, Henan, Republic of China
DiedAugust 10, 2008(2008-08-10) (aged 72)
Alma mater
Known for
Spouse
Helen Hsiang-Yung
​
(m. 1962)​
Children2, including Leslie
MotherLi Xiangheng
RelativesPeter Hessler (son-in-law)
Awards
Scientific career
FieldsSolid-state physics
Institutions
Doctoral advisorGerald Pearson[1]
Leroy Chang
Traditional Chinese張立綱
Simplified Chinese张立纲
Transcriptions
Standard Mandarin
Hanyu PinyinZhāng Lìgāng

Leroy Li-Gong Chang (Chinese: 張立綱; pinyin: Zhāng Lìgāng; January 20, 1936 – August 10, 2008) was a Taiwanese–American solid-state physicist. Born in China, he studied in Taiwan and then the United States, obtaining his doctorate from Stanford University in 1963. As a research physicist, he studied semiconductors for nearly 30 years at IBM's Thomas J. Watson Research Center in New York. This period included pioneering work on superlattice heterostructures with Nobel Prize-winning physicist Leo Esaki.

In 1993, Chang moved from New York to Hong Kong, switching from industrial research into academia in anticipation of the 1997 transfer of the British colony to China. He was among the first wave of recruits to the Hong Kong University of Science and Technology. Over the following 14 years, he helped build the university's reputation in his roles as Dean of Science, Professor of Physics, Vice President of Academic Affairs, and professor emeritus.

Honors bestowed on Chang included memberships of the National Academy of Sciences, the Chinese Academy of Sciences, and Academia Sinica—the national academy of Taiwan. Awards received included the International Prize for New Materials (1985), the David Sarnoff Award (1990), and the Stuart Ballantine Medal (1993). Chang's death in 2008 was marked with memorial services, and a symposium in his memory was held the following year.

Early life and education

Leroy Li-Gong Chang's family was from Jiutai County, Jilin province, in Northeast China (Manchuria).[citation needed] After Manchuria was invaded by Japan in 1931, his family escaped to inland China and Chang was born on January 20, 1936, in Kaifeng, Henan province. His father, Zhang Shenfu [zh], was a well-known geologist and government official who was assassinated by the Communists in 1946, which prompted the family to move to Taiwan.[2] His mother, Li Xiangheng,[3] was one of the first group of women elected to the Legislative Yuan in 1948.[4]

Chang studied electrical engineering at National Taiwan University, graduating with a B.S. in 1957. He emigrated to the United States in 1961 to continue his studies, receiving his Ph.D. in Electrical Engineering from Stanford University in 1963.[5]

Career and research

Between 1963 and 1992, Chang worked at IBM's Thomas J. Watson Research Center in New York.[6] He held the position of researcher for some twelve years (1963–1968; 1969–1975), with a sabbatical year as Associate Professor in the Department of Electrical Engineering at the Massachusetts Institute of Technology (1968–1969).[7] On his return to IBM research, he spent nine years as manager of its Molecular Beam Epitaxy section (1975–1984). This was followed by seven years as manager of the Quantum Structure section (1985–1992).[6] His research included semiconductor physics, low-dimensional electron systems, and nanostructures.[8] In the 1970s, he pioneered development of quantum well and superlattice structure (SLS) techniques.[5]

One of the key results from Chang's work in this period was using molecular beam epitaxy to grow superlattice structures in semiconductors. This research was described in a 1973 paper in the Journal of Vacuum Science and Technology that was cited multiple times over the following years.[9] Eleven years later, in 1984, this pioneering research paper was featured as a Citation Classic by the ISI, an organization that tracks and measures impact factor and citation frequency and volume for journals and individual research papers.[10] Commentary for this retrospective article was provided by Chang.[11] The impact of the research carried out in the 1970s by Chang and his colleagues, including Nobel Prize-winning Leo Esaki and Raphael Tsu, was highlighted by IBM researchers Theis and Coufal in 2004:

Leo Esaki, Ray Tsu, and Leroy Chang began to envision and investigate designed quantum structures — which are based on interfaces between lattice-matched compound semiconductors — early in the 1970s. Ever since, the study of electronic systems of minute dimensions has ranked among the most exciting areas of condensed-matter physics.[12]

After 29 years at IBM, Chang moved from industrial research into academia, being appointed the first Dean of Science at the Hong Kong University of Science and Technology (HKUST) in 1993.[6][13] This was a new university, having been established in 1991. Chang's arrival was described in a 2011 account of the rise of this university: "Other recruits during the first decade included Leroy Chang, a world-renowned experimental physicist from International Business Machines (IBM)."[14] He held the position of Dean of Science until 1998, when he became Vice President of Academic Affairs—stepping down from this role in 2000. From 1997 until his retirement in 2007, he was also University Professor of Physics.[6]

Chang's departure from New York and arrival in Hong Kong in 1993 was part of a wider influx that saw many leading scientists and researchers taking up positions at universities and institutions in the British colony to be able to take advantage of the opportunities presented by the handover of Hong Kong in 1997.[15] Quoted in an article in 1996, Chang stated:

I would never have come to Hong Kong if it was going to remain just a British colony. We came because of 1997.[15]

In addition to his work at HKUST, Chang also supported other science and technology institutions in Hong Kong and the wider region. From 1996 to 1998, he was President of the Hong Kong Institute of Science. In 1998, Chang played a key role in the founding and establishment of the Research Center for Applied Sciences (RCAS) of Academia Sinica in Taiwan, serving on its advisory committee.[5]

Family

In 1961, during his trip to the United States, Chang met Helen Hsiang-Yung, whom he married the following year. They had two children, Justin and Leslie.[16] Leslie is an author and journalist who is married to Peter Hessler, author of several books about China.[17]

Death and tributes

Chang died on August 10, 2008, at the age of 72.[2] Memorial services were held on August 17 at El Camino Memorial Park in San Diego, California,[5] and at the Hong Kong University of Science and Technology.[13] A memorial symposium in his honor, 'Recent Advances in Applied Sciences', was held in 2009 at the Academia Sinica.[18] The symposium program included "A Tribute to Academician Leroy Chang" and "Remembering Leroy: from SL/QW to RCAS".[19] At the time of his death, tributes were paid to Chang by his HKUST colleagues, including the university's founding president Chia-Wei Woo:

Leroy was always exuberant and high-spirited, logical and sensible, forceful and clear, efficient and effective – and always full of wit and humor. As Dean of Science and Vice-President for Academic Affairs, he gave up his beloved and world-renowned scientific career to work totally selflessly towards providing a sound academic environment for his colleagues. HKUST's founding members could not have had a stronger comrade-in-arms in building this new university. I so very deeply mourn his passing.[13]

Recognition

Awards

Country Year Institute Award Citation Ref.
United States 1985 American Physical Society International Prize for New Materials "For their conception of artificial semiconductor superlattices and their recognition that such structures have realizable and would have novel electronic properties" (with Leo Esaki and Raphael Tsu) [20]
United States 1990 IEEE IEEE David Sarnoff Award "For pioneering contributions to the realization and development of quantum wells and superlattices" [21]
United States 1993 Franklin Institute Stuart Ballantine Medal "For applications of semiconductor P" [8]

Memberships

Country Year Institute Type Section Ref.
United States 1982 American Physical Society Fellow Condensed Matter Physics [22]
United States 1988 National Academy of Engineering Member Electronics, Communication & Information Systems [23]
United States 1990 IEEE Fellow [24]
United States 1994 National Academy of Sciences Member Applied Physical Sciences [25]
Taiwan 1994 Academia Sinica Academician [5]
China 1994 Chinese Academy of Sciences Foreign Member [26]

Honorary degrees

Territory Year Institute Degree Ref.
Hong Kong 1995 HKUST Doctor of Science [27]

References

  1. ^ "Leroy Li-Gong Chang - E-Tree". academictree.org. Retrieved November 2, 2025.
  2. ^ a b Leroy L. Chang | Memorial Tributes: Volume 23. 2021. doi:10.17226/26229. ISBN 978-0-309-08602-8. Retrieved November 2, 2025. {{cite book}}: |website= ignored (help)
  3. ^ Leslie T. Chang (2010) Factory Girls: Voices from the Heart of Modern China p95
  4. ^ Li Ao (September 9, 2010). 老脸霸占万年国会. 李敖有话说 (in Chinese). Archived from the original on February 19, 2013. Retrieved February 5, 2013.
  5. ^ a b c d e "Academician Leroy L. Chang Passes Away in USA at Age 73". Academia Sinica E-news. No. 80. Academia Sinica. 2008. Archived from the original on March 4, 2016. Retrieved January 5, 2013.
  6. ^ a b c d "Leroy Chang". Array of Contemporary American Physicists. American Institute of Physics. Archived from the original on May 16, 2013. Retrieved January 5, 2013.
  7. ^ Solid state physics in the People's Republic of China: a trip report of the American Solid State Physics Delegation: submitted to the Committee on Scholarly Communication with the People's Republic of China. Issue 1 of People's Republic of China Series. National Academies. 1976. p. 170. ISBN 9780309025232.
  8. ^ a b "Leroy L. Chang". Franklin Institute. January 15, 2014. Archived from the original on December 21, 2024. Retrieved November 8, 2025.
  9. ^ Chang, L. L.; Esaki, L.; Howard, W. E.; Ludeke, R.; Schul, G. (1973). "Structures Grown by Molecular Beam Epitaxy". Journal of Vacuum Science and Technology. 10 (5). American Vacuum Society: 655–662. Bibcode:1973JVST...10..655C. doi:10.1116/1.1318408. ISSN 0022-5355.
  10. ^ See Garfield, Eugene. "Short History of Citation Classics Commentaries". University of Pennsylvania. Retrieved January 5, 2013.
  11. ^ Chang, Leroy L. (March 19, 1984). "This Week's Citation Classic" (PDF). Current Contents (12). ISI: 18.
  12. ^ Theis, Thomas N.; Coufal, Hans J. (April–May 2004). "How IBM Sustains the Leading Edge". The Industrial Physicist. 10 (2). American Institute of Physics: 18. Archived from the original on January 2, 2013.
  13. ^ a b c "HKUST Mourns Passing of Former Vice-President". Hong Kong University of Science and Technology. August 13, 2008. Retrieved January 5, 2013.
  14. ^ Postiglione, Gerard A. (2011). "Chapter 3: The Rise of Research Universities: The Case of the Hong Kong University of Science and Technology" (PDF). In Altbach, Philip G.; Salmi, Jamil (eds.). The Road to Academic Excellence: The making of World-Class Research Universities. The World Bank. pp. 63–100. ISBN 978-0821388051.
  15. ^ a b Kinoshita, June (May 24, 1996). "Hong Kong's pre-1997 science boom". Science. 272 (5265): 1090–1091. Bibcode:1996Sci...272.1090K. doi:10.1126/science.272.5265.1090. S2CID 179028305. Archived from the original on March 29, 2015 – via HighBeam Research.
  16. ^ "Leroy Chang Obituary (2008)". San Diego Union-Tribune. August 17, 2008. Retrieved November 2, 2025.
  17. ^ 从江城过客到中国行者：海斯勒家族的中国情结 [Hessler's China Connection] (in Chinese). Sina. January 21, 2013. Retrieved February 5, 2013.
  18. ^ "Dr. Leroy Chang Memorial Symposium: Recent Advances in Applied Sciences (introduction)". RCAS, Academia Sinica. Archived from the original on March 3, 2016. Retrieved January 5, 2013.
  19. ^ "Dr. Leroy Chang Memorial Symposium: Recent Advances in Applied Sciences (program)". RCAS, Academia Sinica. Archived from the original on May 8, 2009. Retrieved January 5, 2013.
  20. ^ "James C. McGroddy Prize for New Materials". www.aps.org. Retrieved October 8, 2023.
  21. ^ "IEEE David Sarnoff Award Recipients" (PDF). IEEE. Archived from the original (PDF) on May 9, 2012. Retrieved January 5, 2013.
  22. ^ "Fellows Archive". American Physical Society. Retrieved July 30, 2025.
  23. ^ "Dr. Leroy L. Chang". National Academy of Engineering. Archived from the original on January 20, 2025. Retrieved January 5, 2013.
  24. ^ "Fellows - C". IEEE. Archived from the original on November 2, 2013. Retrieved January 5, 2013.
  25. ^ "Leroy L. Chang". National Academy of Sciences. Archived from the original on August 10, 2025. Retrieved November 2, 2025.
  26. ^ "Backdrop: CAS Foreign Members (1994-2004)". Chinese Academy of Sciences. Archived from the original on February 19, 2013. Retrieved January 5, 2013.
  27. ^ "Honorary Doctorates". HKUST. Retrieved November 1, 2025.
  • Photograph of Leroy L. Chang (1) (Array of Contemporary American Physicists)
  • Photograph of Leroy L. Chang (2) (National Academy of Engineering)
  • Hetero-superlattice PN junctions (US Patent 5416337)
  • Superlattice ultrasonic wave generator (US Patent 4469977)
  • Consolidation with an Eye to the Future, 1999 interview with Chang as new Vice-President for Academic Affairs (HKUST)
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