He discovered a new state of matter called topological insulator in which electrons can conduct along the edge without dissipation, enabling a new generation of electronic devices with much lower power consumption. For this ground breaking work he received numerous international awards, including the Buckley Prize, the Dirac Medal and Prize, the Europhysics Prize, the Physics Frontiers Prize and the Benjamin Franklin Medal.
Zhang was a postdoctoral Fellow at ITP in Santa Barbara from 1987 to 1989. He then joined IBM Almaden Research Center as a Research Staff Member from 1989 to 1993. Thereafter, he joined Stanford University as Assistant Professor of Physics. Beginning in 2004, he concurrently held (by courtesy appointment) titles of Professor of Applied Physics and Professor of Electrical Engineering at Stanford University. In 2007, the "quantum spin Hall effect" discovered by Zhang was named one of the "Top Ten Important Scientific Breakthroughs in the World" by Science Magazine. In 2010, he was named the J. G. Jackson and C. J. Wood Professor in Physics.[3]
In 2009, Zhang was chosen to be a part of an expert panel for the Thousand Talents Program. In 2013, Zhang created Danhua Capital, a venture capital firm, which raised $434.5 million across two funds.[2] Danhua Capital's major investors include state-owned Beijing government enterprise Zhongguancun Development Group (ZDG), which has been linked to the Chinese technology transfer program Made in China 2025.[4] He also served as an independent non-executive director at Lenovo Group and at Meitu.[5]
Zhang's wife Barbara is a software engineer at IBM. They met in kindergarten, in Shanghai. Together they have two children, a son Brian and a daughter Stephanie.[6]
Zhang died in San Francisco on December 1, 2018, at the age of 55, in an apparent suicide. His family said in a statement that he died "after fighting a battle with depression."[7][8][9]
Scientific achievements
Zhang was one of the founders of the field of topological insulators. He made one of the first theoretical proposals of the quantum spin Hall effect. Soon after the initial theoretical proposal, his group theoretically predicted the first realistic quantum spin Hall material in HgTe quantum wells.[10] This prediction was soon confirmed experimentally,[11] launching worldwide research activities. Subsequently, his group predicted numerous novel topological states of matter and topological effects, including the Bi2Se3 family of 3D topological insulators,[12] the topological magneto-electric effect,[13] the quantum anomalous Hall effect in magnetic topological insulators, time-reversal invariant topological superconductors, and the realization of a chiral topological superconductor and of chiral Majorana fermions using the quantum anomalous Hall state in proximity with a superconductor. Most of these predicted properties have now been experimentally observed.
Earlier, Zhang also made significant contributions to other areas of physics. He and collaborators derived a topological (Chern–Simons form) quantum field theoretic description of the novel properties of fractional quantum Hall liquids,[14] and proposed a global phase diagram for the quantum Hall states with many features that have had since been experimentally observed. He generalized the theory of fractional quantum Hall effect to higher dimensions and related it to fundamental particle physics. He also proposed an influential theory of high-temperature superconductivity based on an extended symmetry principle.[15]
In early 2000, Zhang and collaborators revitalized the field of spintronics by proposing an intrinsic spin Hall effect and relating it to geometrical phases in quantum mechanics. This proposal stimulated extensive theoretical and experimental work, and also contributed to later developments concerning the quantum spin Hall effect and topological insulators more generally.
Between the years 2010–2015, Zhang and his group of physicists at Stanford University wrote three theoretical papers where they successfully showed how to test Ettore Majorana's theory of Majorana fermion, or what had previously been only a scientific hypothesis that a particle can be its own antiparticle, without the need of external forces having the same mass with the opposite charge of the electron.[16]
^Zhang, H. J.; et al. (2009). "Topological insulators in Bi2Se3, Bi2Te3 and Sb2Te3 with a single Dirac cone on the surface". Nature Physics. 5 (6): 438–442. Bibcode:2009NatPh...5..438Z. doi:10.1038/nphys1270.
^Zhang, S. C. (1992). "The Chern–Simons–Landau–Ginzburg theory of the fractional quantum Hall effect". International Journal of Modern Physics B. 6 (1): 25–58. doi:10.1142/S0217979292000037.
^ ab"Topological quintet bags Europhysics prize". Physics World. June 21, 2010. Retrieved December 7, 2018. Five physicists who brought us the quantum spin-Hall effect and topological insulators have been awarded this year's Europhysics Prize from the European Physical Society's condensed-matter division. The winners are Shoucheng Zhang of Stanford University; Charles Kane and Eugene Mele of the University of Pennsylvania; and Hartmut Buhmann and Laurens Molenkamp of Würzburg University in Germany.
^"Oliver E. Buckley Condensed Matter Prize". Aps.org. July 27, 2011. Retrieved December 7, 2018. For the theoretical prediction and experimental observation of the quantum spin Hall effect, opening the field of topological insulators.
^"Laureates: Shoucheng Zhang". BreakthroughPrize.org. 2013. Retrieved December 7, 2018. 2013 Physics Frontiers Prize in Fundamental Physics: For the theoretical prediction and experimental discovery of topological insulators
^"Shoucheng Zhang". Franklin Institute. 2015. Retrieved December 7, 2018. Citation: With Charles Kane and Eugene Mele, for their groundbreaking theoretical contributions leading to the discovery of a new class of materials called topological insulators, and for their prediction of specific compounds exhibiting the novel properties expected of these new materials.
