Hui-Chun Liu

H.C. Liu passed away on October 23, 2013, at the age of 53, due to a bad fall which resulted with the last nine days of his life in a coma. His sudden and unexpected death is a shock to the physics community, and our heart goes out to his wife, Xiang Zhang, and son, Haru Greco-Liu.

Hui-Chun Liu, known in the scientific community as “H.C.”, was born in the city of Taiyuan, China, in 1960. He received his BSc in physics from Lanzhou University, China, in 1982. After successfully passing the selection process of the 2nd-year CUSPEA program, he went to University of Pittsburgh, USA, where he received his PhD in applied physics in 1987 as an Andrew Mellon Predoctoral Fellow. Prof. Liu’s major research interest was semiconductor nanoscience and quantum devices.

H.C. joined the Institute for Microstructural Sciences of the Canadian National Research Council as a Research Associate in 1987 and rose rapidly through the ranks, becoming Principal Research Officer – the highest research rank, reserved for very few – in 2000. He became the Institute’s Terahertz & Imaging Devices Group Leader. In 2011 he took a position at the Shanghai Jiao Tong University in China, where he built up a new research group as a “1000 talents” Chair Professor. He founded two high-tech companies in China, Debut Optoelectronic Sensors in Wuxi, and Ghopto Shanxi Guohui Optoelectronic Technology in Taiyuan.

H.C. was elected APS Fellow in 2004, IEEE Fellow in 2007, and became member of the Academy of Sciences at the Royal Society of Canada in 2008. He has been granted over a dozen patents, and was awarded the Herzberg Medal from the Canadian Association of Physicists in 2000, Bessel Prize from the Alexander von Humboldt Foundation in 2001, Chinese Overseas Distinguished Young Scientist Award (NSFC-B) in 2005, Changjiang Scholar Award in 2008, and Jiangsu provincial high-level innovation-entrepreneur talent award in 2011. He authored or coauthored more than 380 refereed journal articles (with about 95 as first or sole author), and gave 95 invited presentations at international conferences. He held adjunct/guest/honorary professorships in 10 institutions in Canada, China, and the USA.

When H.C. was still in graduate school in the 80’s, the field of intersubband transitions in semiconductor quantum wells (QW) was born. Along with others, H.C. pioneered the field of QW infrared photodetectors (QWIPs). As a junior researcher at Canadian NRC, H.C. started a world-leading research program on QWIPs. The ultrafast QWIP technologies that he developed are being used in leading research labs and industries, including Harvard, ETH-Zürich, UC-Berkeley, Northrop Grumman, and GE Nuclear. His patented upconversion pixelless imagers have attracted considerable attention, as well as the recent extension of QWIPs into the terahertz (THz) spectral region that he pioneered.

H.C. Liu was a recognized world leader in the area of intersubband transitions in QWs and dots, as evidenced by the editorship of two volumes in the prestigious series of Semiconductors and Semimetals. He was also a recognized world leader in QWIP physics and technology and his name is often viewed as a proxy of QWIP, as evidenced by the authorship of a monograph on the subject and by his service as chair/co-chair of various QWIP workshops and the International Conference on Intersubband Transitions in Quantum Wells (ITQW, twice). He was member of several steering and advisory committees overseeing the strategic development of THz technology in China.

Besides being the undisputed leader in the field of QWIPs, he also demonstrated two-photon absorption in QWIPs, studied various non-linear optical phenomena through intersubband transitions, and developed an intersubband Raman laser. Early in his career, he did innovative analysis on resonant tunneling diodes. Recently, he began to make impact on the field of THz quantum cascade lasers (QCLs). H.C. developed these devices, and together with his collaborators, achieved a record performance in the operating temperature, which is significant as increasing operating temperature of THz QCL is the most important challenge in this field.

In addition to his extensive scientific achievements, H.C. Liu was a very close friend to many of his colleagues, sometimes like a brother, always positive. A unique leader, he was always generous and fiercely protective of his staff, attentive to their well-being, and knew instinctively how to draw out the best skills of each team member, instilling a common sense of purpose in all. His calm and positive demeanor had a positive influence on his colleagues and especially on his students.

His unfailing support and loyalty will be deeply missed and he will always be fondly remembered.

Submitted by:

Harald Schneider, HZDR, Dresden, Germany

Qing Hu, MIT, Cambridge, USA

Emmanuel Dupont, NRC, Ottawa, Canada

Xi-Cheng Zhang, U. Rochester, USA

Chao Zhang, U. Wollongong, Australia

Jun-Cheng Cao, SIMIT, Shanghai, China