Xiaoxing Xi

Xiaoxing Xi (Chinese: 郗小星, p Xī Xiǎoxīng; b. 1958) is a Chinese-born American physicist. He is Laura H. Carnell Professor of Physics at Temple University in Philadelphia, and was chairman of Temple's physics department. In May 2015, the United States Department of Justice arrested him on charges of having sent restricted American technology to China. In September 2015, he was completely cleared and the charges against him dropped, when independent scientists discovered that the prosecutors had misconstrued or misunderstood the evidence against him. Despite this the US government has not paid Xi compensation in any form. This case has been highlighted as an example of how Asian-Americans have suffered systemically from racism.

Xi was born in China and received his Ph.D. from Peking University in 1987. He was a researcher at the Karlsruhe Nuclear Research Center in Germany, Bell Communication Research at Rutgers University, and University of Maryland, before becoming a faculty member of Pennsylvania State University in 1995. He moved to the United States in 1989 and has become a naturalized US citizen. Xiaoxing Xi's wife is also a physics professor, who teaches at Pennsylvania State University. They have two daughters. They live in suburban Philadelphia. He was named chairman of Temple University's physics department in 2014.

Spy case

In May 2015, the United States Department of Justice accused him of sending restricted American technology to China: specifically, the design of a pocket heater used in superconductor research. Xi was arrested by about a dozen FBI agents at his home, and faced charges carrying a maximum penalty of 80 years in prison and a $1 million fine. He was put on administrative leave by Temple University, and resigned as chairman of the physics department.

In September 2015, however, the DOJ dropped all charges against him after leading scientists, including a co-inventor of the pocket heater, provided affidavits that the schematics that Xi shared with Chinese scientists were not for a pocket heater or other restricted technology. According to Xi's lawyer Peter Zeidenberg, the government did not understand the complicated science and failed to consult with experts before arresting him. He said that the information Xi shared as part of "typical academic collaboration" was about a different device, which Xi co-invented and which is not restricted technology.

• The National Science Foundation's Career Award (1997)
• Chang Jiang Scholar (2006), bestowed by the Chinese Ministry of Education and the Li Ka Shing Foundation
• Fellow of the American Physical Society (2007)

Xiaoxing Xi has published more than 300 research papers and holds three patents. His research focus is on materials physics, specifically the applications of epitaxial thin films and nanoscale heterostructures. His key publications include:

• Xi, X.X.; et al. (2002), "In situ epitaxial MgB2 thin films for superconducting electronics", Nature Materials, 1: 35–38, doi:10.1038/nmat703 .
• Xi, X.X. (2008), "Two-band superconductor magnesium diboride", Reports on Progress in Physics, 71: 116501, doi:10.1088/0034-4885/71/11/116501 .
• Xi, X.X.; et al. (2012), "Momentum-dependent multiple gaps in magnesium diboride probed by electron tunnelling spectroscopy", Nature Communications, 3: 619, doi:10.1038/ncomms1626 .
• Xi, X.X.; et al. (2013), "Exploiting dimensionality and defect mitigation to create tunable microwave dielectrics", Nature, 502: 532–536, doi:10.1038/nature12582, PMID 24132232 .
• Xi, X.X.; et al. (2014), "Atomically precise interfaces from non-stoichiometric deposition", Nature Communications, 5, doi:10.1038/ncomms5530 .