Loss of a Scientific Genius

At the top of a hill, Zhang stopped the car, and casting his eye over the tech giants and startups of Silicon Valley below, said: “We have to aim high and pursue theories that can fundamentally solve problems and become game-changers, rather than making minor changes within the old framework.”　　

Back then, the 43-year-old scientist had already been a tenured professor of physics at Stanford University for 11 years, where he was best known for his innovative research on topological insulators – materials which have insulating material on the inside, but can conduct electrons on the surface. Nobel laureate and Chinese physicist Chen-Ning Yang, who was Zhang’s mentor at Stony Brook in New York, predicted that it was only a matter of time before Zhang was awarded a Nobel Prize. But on December 1, 2018, the world of physics was rocked by the news that Zhang, 55 and a married father of two, had “passed away unexpectedly after a battle with depression,” according to an email from his family obtained by the South China Morning Post. A spokesperson for the family later told the paper that Zhang had committed suicide.　　

His scientific peers, both in China and around the world, united to describe his death as an inconceivable loss to the world of physics.　　

Academic Star　

Born in 1963 to a family of engineers in Shanghai, Zhang, something of a child prodigy, was admitted to the city’s Fudan University when he was only 15, later going on to study physics at the Free University of Berlin in Germany in his second year. In the summer of 1981, he toured around Germany and arrived at the University of Gottingen. At a graveyard near the university, Zhang visited the tombs of many famed physicists who were often cited in his textbooks. Zhang discovered that the gravestones were inscribed with either their words or equations.　　

Zhang was deeply moved and decided to devote himself to theoretical physics. During an interview with Ifeng Finance in 2017, he said that a human could have many lifetime aspirations, but the greatest thing is what a scientist leaves for the next generation. These mathematicians and physicists have made great contributions to the world, and their greatness was what Zhang was trying to emulate.　　

After earning a PhD in 1987 at the State University of New York at Stony Brook, Zhang focused his research on condensed matter. In 2006, Zhang and his research team successfully predicted the quantum spin Hall effect inside topological insulators–a part of string theory. In 2013, the prediction was confirmed experimentally, starting a new round of research activities worldwide. Because of his pioneering research in topological insulators, Zhang was awarded virtually all the awards in the field of physics, including the Europhysics Prize in 2010, the Dirac Medal in 2012, and the Physics Frontier Prize in 2013. On November 3, 2014, Zhang received the Benjamin Franklin Medal, only the second Chinese-American scientist to obtain the prize after Chen-Ning Yang.　　

Zhang Shoucheng’s research also focused on high-temperature superconductivity, also the research area of Zhang Fuchun, director of the Institute of Theoretical Physics under the Chinese Academy of Sciences (CAS). Since 1990, they maintained regular academic contact. In early 2000, Zhang Fuchun was a researcher at Hong Kong University and Zhang Shoucheng was academic advisor to the university’s Center of Theoretical and Computational Physics.　　

Zhang Fuchun told our reporter that Zhang Shoucheng was very demanding when it came to hotels and food, always requesting access to a swimming pool. Whenever he visited Hong Kong University, he would book his own accommodation.“Zhang Shoucheng suffered from insomnia and he had to swim for a while before he could sleep. Many theoretical physicists have sleep problems, and Zhang’s case was not severe,” said Ding Hong, a researcher with the Institute of Theoretical Physics of CAS, who was also a friend of Zhang.　　

Qi Xiaoliang, one of Zhang Shoucheng’s postdoctoral students, worked with the physicist for more than 10 years. Zhang Shoucheng said publicly several times that Qi, now an associate professor in physics at Stanford, was his best student. Qi told our reporter that Zhang was a trailblazer in several fields such as quantum spin Hall effect, high-temperature superconductivity and topological insulators.　　

“Professor Zhang predicted a number of new materials and physical phenomena including the Majorana fermion,” Qi told NewsChina. In July 2017, Zhang and his team discovered solid evidence for the existence of Majorana fermion (or particle), a fermion that is its own antiparticle, which was first predicted in 1937 but whose existence had not been confirmed for 80 years. The findings were later published in the journal Science. Zhang argued that Majorana fermions could be applied to quantum computers which are unlikely to be affected by any environmental noise. Zhang named Majorana fermions the “angel particles,” arguing that it was just like discovering a perfect world where there are only angels and no devils.　

Dai Xi of HKUST told our reporter that Zhang was “a lantern that lights up the entire circle of theoretical physics.” Dai added that after a dinner at an academic conference, Zhang explained to Dai in great detail the mathematical principles of Bitcoin and blockchain technologies through writing on a napkin. “I’d read several books about blockchain, but no writers could explain it so concisely and clearly,” he told NewsChina.　

New Venture　

Since childhood, Zhang had always had a wide range of interests. When he was a high school junior, he happened to read a story about inventor Benjamin Franklin, famous for flying a kite during a storm to explore the properties of electricity. Several years later, Zhang came to learn that Franklin, one of the Founding Fathers of the US, was also a statesman, entrepreneur, diplomat and writer.　　

“Franklin’s life taught me that a scientist has to shoulder more social responsibilities. Scientific discoveries should benefit the human race and turn into scientific products through enterprises,” Zhang said during a speech he made at a ceremony in 2017 after he was given the You Bring Charm to the World Award, which has been annually organized by Phoenix Satellite Television since 2006.　　

Zhang liked to compare human knowledge to a tree and each academic subject as a single branch. Alongside the development of academic research, he said, scientists are increasingly distant from each other, so it is time to find the “root” of scientific research as well as the common characteristics of knowledge. He thought the world lacked polymaths like Franklin, who are skilled in a number of fields. Zhang, after he made breakthroughs in physics, found his new mission as a venture capitalist.　　

In September 2013, Zhang established Digital Horizon Capital, also known as Danhua Capital, a venture capital firm focusing on artificial intelligence, big data, healthcare and blockchain in Silicon Valley. He had maintained cooperation with several top Chinese universities, including Peking University, Shanghai Jiao Tong University and Tsinghua University, but he discovered that while innovative in business concepts, these top Chinese institutions were relatively weak in fundamental sci-tech innovation.　　

According to Zhang Shoucheng, even though scientists are great inventors and innovators, most suffer from lack of experience in startups and investment. He created Danhua Capital in order to combine cutting-edge technologies and investment, and cement ties between China and the US in both business and technology. During an interview with Phoenix TV in 2017, Zhang commented that virtually 80 to 90 percent of Chinese internet companies had invested in Danhua Capital.　　

From November 19 to 20, 2018, the Workshop for Topological Quantum Information was held at Shanghai Tech University and Zhang was one of its chairs. The university was scheduled to inaugurate its Topological Quantum Laboratory headed by Zhang, but it was postponed indefinitely because Zhang did not show up for the meeting. 　　

Ding Hong, a researcher with the Institute of Theoretical Physics at CAS, told our reporter that before the conference, Zhang suffered from a bad cold and a severe cough, which had affected his sleep. Zhang wanted to fly to China for the meeting but was prevented by his doctor. Ding Hong took a picture of the laboratory and sent it to Zhang, but he received no reply.　　

The last time Ding met Zhang Shoucheng was in June 2018, when Ding visited Stanford. Ding said he dined with Zhang, Zhang’s wife and another Stanford professor. They talked about international relations, history and culture and many other things. “I didn’t notice anything different about him. Perhaps it was very personal and only his family members knew about it [the depression],” Ding told NewsChina.　　

Sean McCormack, spokesperson for Zhang Shoucheng’s family, told our reporter that until his death, his family members did not realize that he suffered from depression and it was extremely difficult for his close family to discover Zhang’s struggles.　　

On December 9, 2018, Chen-Ning Yang said in an article honoring Zhang’s achievements published in the Beijing-based Guangming Daily, that in the world of physics, it was generally agreed that Zhang, along with fellow scientists Charles L. Kane, a theoretical condensed matter physicist and professor of physics at the University of Pennsylvania who shared the 2012 Dirac Prize with Zhang, and Dutch physicist Laurens W. Molenkamp were a shoe-in for future Nobel honors, and despite the tragic loss of his former student, he expects Molenkamp and Kane will go on to receive the prize.　　

More than 10 years ago, Zhang posed for a group photo with Qi Xiaoliang and several other students he supervised after they had hiked up a mountain, although the location was not given. The group was pictured at the summit looking at the sunrise. On December 8, 2018, Qi posted the picture on his We- Chat account and wrote “Professor Zhang is on the other side of the horizon. We will never see him again, but he can always see us.”