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Wendy Mao, Stanford’s Earth Sciences Chair and Deputy Director of Stanford’s Institute for Materials and Energy Sciences at SLAC, has co-authored over 50 publications, trained five employees, and maintained a visiting scholar position at HPSTAR, an “alias” for China's nuclear weapons program.
In 2020, the Center for High Pressure Science and Technology, or HPSTAR, was added to the U.S. Department of Commerce's Entity List, which identifies organizations that pose a significant risk to national security. Since its 2020 Entity List designation, Professor Mao has co-authored at least 12 peer-reviewed papers with HPSTAR.
The U.S. Entity List describes HPSTAR as an organization “owned by, operated by, or directly affiliated with the Chinese Academy of Engineering Physics (CAEP), which is the technology complex responsible for the research, development and testing of China's nuclear weapons and has been on the Entity List under the destination of China since June 30, 1997.”
According to Canada's 2024 Named Research Organizations List, HPSTAR is an “alias” for the institution behind China’s nuclear weapons program.
HPSTAR studies how materials behave under extreme pressures and temperatures using diamond-anvil cells, synchrotron beams, and X-ray diffraction. Mao is a leading U.S. researcher in this very field.
In an interview with the Stanford Review, Professor Raymond Jeanloz, a UC Berkeley high-pressure materials researcher and former chair of the National Academy of Sciences Committee on International Security and Arms Control, stated:
"It is true that high-pressure experiments are used by scientists working on the domain of nuclear weapons. If anyone is using the diamond anvil cell or shock waves to study materials relevant to nuclear weapons, that's highly sensitive. If those same methods are then applied to sensitive nuclear materials, the combination of these kinds of experiments with these materials starts raising eyebrows."
Both Mao and HPSTAR extensively use diamond anvil cells and shock waves to study materials.
Mao and HPSTAR’s public research papers do not directly involve weapons testing, design, or development. However, these precise high-pressure measurements and theoretical knowledge are the necessary foundations of modern nuclear and advanced weapon design, where accurate modeling of materials under detonation-level conditions is critical.
Professor Mao Collaborates With Alias for China’s Nuclear Weapons Program
Over the past two decades, Mao has co-authored at least 50 publications with HPSTAR. Funding acknowledgments show that Wendy Mao and HPSTAR co-authored research financed by the following U.S. government agencies:
- Department of Energy (including the National Nuclear Security Administration (NNSA), Argonne National Laboratory, Lawrence Berkeley National Laboratory, Oak Ridge National Laboratory, and Brookhaven National Laboratory)
- Defense Advanced Research Program Agency (DARPA)
- Department of Defense (DOD)
- National Science Foundation (NSF)
- National Institutes of Health (NIH)
- Army Research Office (ARO)
- National Aeronautics And Space Administration (NASA)
Trained HPSTAR PhD students
Mao has trained at least five HPSTAR employees as PhD students in her Stanford and SLAC labs. At least one HPSTAR postdoctoral researcher simultaneously worked on DOE, NNSA, and DARPA-funded research at SLAC.
For example, one of Mao’s current PhD students worked at HPSTAR for three years, from 2015 to 2018, receiving an M.S. in Condensed Matter Physics before joining Stanford as a PhD student in Mao’s lab.
The other four were trained in Mao’s lab and returned to China to work at HPSTAR. These are only the individuals we were able to identify via web and archival searches.
In an interview with the Review, a high-ranking Trump 45 official with knowledge of the matter stated, “Mao has trained 5 PhD students affiliated with China’s nuclear weapons program. Stanford should not permit its federally funded research labs to become training grounds for entities affiliated with China’s nuclear program. Mao’s continued and extensive academic collaboration with HPSTAR is adequate grounds for termination.”
Visiting Scholar at HPSTAR
Mao served as a visiting scholar at HPSTAR’s Shanghai laboratory from at least 2016 to 2019. She also maintains a HPSTAR email address. Her internal Stanford CV and profile list 43 affiliations, but they do not disclose her position at HPSTAR.
In an interview with the Review, LJ Eads, a China research-security expert and developer of Data Abyss, a platform that analyzes U.S.–Chinese research collaboration, stated, “For someone with access to SLAC and other national labs, foreign affiliations must be disclosed under DOE Order 486.1A. Dr. Mao’s undisclosed HPSTAR role and active HPSTAR email raise legitimate concerns about whether federal disclosure rules were followed and whether Stanford had the information needed to manage foreign-influence risk.”
As a professor with appointments at SLAC National Accelerator Laboratory and other sensitive national labs, Mao is subject to this disclosure requirement. Mao did not respond to a request for comment regarding her compliance with this requirement.
CAEP Affiliation
Mao has also co-authored papers in Matter and Radiation at Extremes, a journal owned by CAEP, China’s nuclear development organization. She did so under a 2020 article titled "Key problems of the four-dimensional Earth system."
The respective organizations responsible for the development of the U.S. and China’s nuclear weapons programs, the U.S’s National Nuclear Security Administration and CAEP’s National Security Academic Fund, are co-funders for several of Mao’s projects.
China’s nuclear program started the National Security Academic Fund to strengthen “exploratory national security basic scientific research.” According to leaked documents from China’s nuclear program, translated by Georgetown University, “The NSAF Fund has broken new ground for CAEP in attracting technological forces across China to start basic research with the pulling force of national security requirements.”
Mao is listed as a co-author, contributing the aforementioned “national security basic research,” to at least 6 NSAF-funded research projects with HPSTAR collaborators. In funding acknowledgments, HPSTAR is described as an institution “supported by [CAEP’s] NSAF (grant no: U1530402).”
Wolf Amendment Concerns
On November 23, 2024, Mao was published as a co-author on a paper titled “Iron Bonding with Light Elements: Implications for Planetary Cores Beyond the Binary System.” Wenzhong Wang, from the University of Science and Technology of China, is listed as a collaborator. This paper also acknowledges funding from NASA’s Exoplanet Program.
The Wolf Amendment prohibits the use of NASA grants from collaboration “with institutions of the People’s Republic of China.” According to NASA’s document on the matter, “that means that it's not enough that a NASA grantee simply avoids sending funds to PRC; rather, the grantee may not spend any NASA grant money on any part of a bilateral project with PRC.”
Eads also noted: “The Wolf Amendment bars NASA-funded researchers from participating in bilateral projects with Chinese institutions unless a waiver is granted. When a NASA-supported Stanford professor co-authors research with a scientist from a PRC university, the burden is on the institution to show an exemption. Stanford-Mao doesn't have an exemption. Without one, this places the work squarely in a serious Wolf Amendment risk area.”
The Review was unable to verify whether authorization for an exception was granted. Mao did not respond to a request for comment regarding her compliance with this requirement.
Export Control Requirements
As recently as September 12, 2025, Mao published a paper with three HPSTAR co-authors. The research paper featured HPSTAR researchers using cutting-edge equipment at U.S. government laboratories, including X-ray diffraction conducted by the High Pressure Collaborative Access Team at Argonne’s Advanced Photon Source, the Beamline 12.2.2 at Lawrence Berkeley’s Advanced Light Source, and XRD measurements supported by the National Nuclear Security Administration.
Eads further commented:
“Fundamental research is generally legal, but export controls still apply to hands-on access to sensitive equipment. When export-controlled lasers at SLAC or national laboratories intersect with Stanford HPSTAR-linked students [Mao’s SLAC-trained PhD students] and collaborators, it creates a real risk of transferring controlled U.S. technology and know-how to a PRC-aligned institution.”
The same aforementioned official from Trump 45 also stated, “HPSTAR should not have been granted access to or use of DOE national laboratories. Mao and her collaborators very likely facilitated the use of export-controlled items, including those regulated under the Export Administration Regulations, Category 6, such as sensors and lasers, and Category 3, including electronics and X-ray detectors, for HPSTAR, an institution affiliated with China’s nuclear weapons program. This is a shocking lapse of research security.”
Access to US National labs
For example, a research project was authored by Wendy Mao, Jin Liu of HPSTAR (formerly a PhD student in Mao’s lab), and Yue Meng of Argonne National Laboratory, among others. The research is “supported by the National Nuclear Security Administration… acknowledges… the use of computing resources from Brookhaven National Laboratory… and X-ray diffraction… conducted at Argonne National Laboratory… HPSTAR is supported by NSAF.” In this case, the NNSA and CAEP’s NSAF are co-funding Chinese “exploratory national security basic scientific research,” using sensitive national laboratories
Eads told the Review that “Dr. Mao effectively provides HPSTAR-linked scientists access to U.S. national-lab resources, training, equipment, and funded research, through her positions at Stanford and SLAC. That kind of access is exactly what China’s research system tries to cultivate abroad.”
In 2023, Chairman Mike Lee of the Senate Committee on Energy and Natural Resources wrote a letter warning “Oak Ridge, Los Alamos, and Argonne National Laboratories regarding reports that researchers at all three labs have engaged in research collaborations leveraging… the PRC’s military for federally funded research in sensitive fields.”
Miscellaneous Defense Lab Affiliations
Beyond HPSTAR and CAEP, Wendy Mao conducted research with the Beijing Institute of Technology and Northwestern Polytechnical University (NWPU). Both institutions are part of China’s Seven Sons of National Defense: key research institutions for the Chinese military. These publications acknowledge co-funding from the Department of Energy and DARPA.
Wendy Mao also conducted research with Shanghai Jiao Tong University's National Key Laboratory of Science and Technology on Nano Fabrication, which is also a key Chinese military-designated laboratory.
China’s Nuclear Programs: A History of Academic Espionage
Wendy Mao’s father, Ho-Kwang Mao, was one of the leading U.S. experts in high-pressure physics, a fundamental science behind nuclear weapons development.
He led the National Nuclear Security Administration's (NNSA) co-sponsored Carnegie-DOE Alliance Center (CDAC). Under his supervision, the center collaborated with and trained NNSA’s staff to ensure nuclear-weapons readiness and stockpile maintenance. Upon recruitment by CAEP in 2012, Ho-Kwang Mao established HPSTAR as a subordinate institution.
Failure of Research Security
Drawing on testimony from China specialists, high-pressure materials scientists, and publicly available documents, our investigation confirms that Professor Wendy Mao has maintained extensive collaboration with organizations advancing China's Nuclear Program. This raises a fundamental question: how should U.S. institutions respond? What is clear is that the status quo of inaction is untenable.
Over a year ago, Eads presented documentation of Mao’s collaborations—including her formal role at HPSTAR—to the Department of Energy, the FBI, and Stanford University. Yet federal agencies, including the DOE, DoD, DARPA, and multiple national laboratories, continue to fund research that intersects with U.S.-listed entities such as HPSTAR.
To be clear, export-control restrictions, foreign-affiliation disclosure rules, and potential Wolf Amendment issues remain relevant. But the bulk of Mao’s work with HPSTAR appears to fall under the federal definition of fundamental research, meaning the results are “published and shared broadly, with no restrictions for proprietary or national-security reasons.” Under current law, such collaboration with a U.S.-listed entity is generally permitted.
Wendy Mao’s case is not an outlier. It is a revealing example of a much larger institutional problem at Stanford. As Eads explains, “Mao’s case isn’t isolated. When I analyze Stanford publications, I find at least 1,300 papers involving entities tied to China’s military-civil fusion system. It’s a broader pattern of collaborations that link Stanford researchers to PRC institutions with clear defense relevance.”
In a world where the nation that develops superior technologies gains a decisive advantage, the United States cannot afford strategic complacency. Protecting America’s scientific infrastructure demands a coordinated response. Stanford University and the federal government must take serious, overdue steps to ensure the integrity of mission-critical research.
Professor Mao did not respond to a request for comment.
Author's Note
This article is the second in a series covering the Chinese Communist Party's influence at Stanford. To stay informed as details emerge, consider subscribing to the Stanford Review. If you have any relevant information about this topic, send it to investigations@stanfordreview.org. To support our work, please donate here.
This investigation is based on publicly available government documents, academic publications, archival records, and interviews with independent research and security experts and academics. This article is a work of journalism and public-interest reporting. It does not offer legal conclusions in any form.
This issue was first identified and investigated by LJ Eads, a China research-security expert and developer of Data Abyss, a platform that analyzes U.S.–Chinese research collaboration. Having brought this to our attention, the Stanford Review initiated an investigation.
