Correlations, criticality, and coherence in quantum systems

Évora, Portugal, 6-10 October 2014

This workshop is dedicated to the memory of
Shi-Jian Gu,
speaker of a previous workshop held in Évora

In Memoriam - Shi-Jian Gu
(Speaker in the Workshop on Correlations and Coherence in Quantum Matter
Évora, Portugal, 10-14 November 2008)

My long time best friend, Shi-Jian Gu, an outstanding young condensed matter theorist, passed away on September 28, 2014 at the untimely age of 40, following a five year battle with cancer. My great sorrow is beyond words. My memories of Shi-Jian go back to the year 2000, when we embarked upon our first collaboration, a study of the Kondo system, and coauthored a paper on that subject. At that time, Shi-Jian was a Ph.D. student. He went on to win China’s National top 100 best Ph.D. thesis award. He also was a member of the team which won a 2nd class in the highly prestigious Chinese National Natural Science Award.

Shi-Jian visited the Chinese University of Hong Kong (CUHK) in 2003 and joined CUHK in 2004, remaining there until his death. Over the years, including in the period 2009-2014, when he was suffering from cancer, he educated several students and postdoctoral fellows, taught undergraduate as well as graduate courses, and contributed to the physics department in many ways. 

Shi-Jian’s research areas were condensed matter theory and quantum information. I will not go into details on Shi-Jian’s contributions, other than to point out that three of his works he did while in Hong Kong, one on a spin model, one on a fermion model, and another where the fidelity susceptibility was invented, each attracted great attention. The famed Web of Science placed the latter work among the top 1% important papers  in 2007 in that extremely vital field. It is not an exaggeration to say that Dr. Gu pioneered the use of fidelity susceptibility in identifying quantum phase transitions.  His contributions were widely acknowledged. His review article on fidelity susceptibility attracted considerable interest and provoked many subsequent investigations. Last year, Shi-Jian was nominated to 2014 年度陈嘉庚青年科学奖.

Aside from being an outstanding young scientist, Shi-Jian's easy-going personality was manifested when working with his students, postdoctoral fellows, and senior scientists. He was highly motivated, very hard-working, and intensely interested in science, while at the same time exhibiting courage and toughness in dealing with his tragic illness. Four days before his premature death, one of his recent works was accepted for publication in Europhysics Letters. The loss of Shi-Jian to his family, friends, and students is incalculable. We can only wish that he has gone in peace. He will be forever remembered by those of us fortunate to have known him.

Shi-Jian, one of my life’s greatest treasures has been having you as a collaborator and friend. If there will be a second life, I wish to be your friend and to work with you once again.

Hai-Qing Lin