Steven Chu

Steven Chu
Born	Steven Chu (朱棣文) 28 2, 1948
Birthplace	St. Louis, Missouri, U.S.
Nationality	American
Occupation	Physicist, academic, former government official
Title	William R. Kenan Jr. Professor of Physics and Professor of Molecular and Cellular Physiology, Stanford University
Known for	Cooling and trapping of atoms with laser light; service as 12th U.S. Secretary of Energy
Education	University of California, Berkeley (MS, PhD)
Children	2
Awards	Nobel Prize in Physics (1997)
Website	[http://www.stanford.edu/dept/physics/people/faculty/chu_steven.html Official site]

Steven Chu (Template:Zh; born February 28, 1948) is an American physicist, academic, and former government official who shared the 1997 Nobel Prize in Physics with Claude Cohen-Tannoudji and William Daniel Phillips for their independent development of methods to cool and trap atoms with laser light. Chu served as the 12th United States Secretary of Energy under President Barack Obama from January 21, 2009, to April 22, 2013, becoming the first Nobel Prize–winning scientist to serve in a presidential cabinet. He is currently the William R. Kenan Jr. Professor of Physics and Professor of Molecular and Cellular Physiology at Stanford University. Throughout his career, Chu has worked across the fields of atomic physics, biological physics, and polymer physics, conducting research at Bell Laboratories, Stanford University, and the University of California, Berkeley. A vocal advocate for renewable energy and nuclear power, Chu has argued that a transition away from fossil fuels is essential to addressing climate change, and he continues to lecture internationally on paths toward achieving net-zero greenhouse gas emissions.

Early Life

Steven Chu was born on February 28, 1948, in St. Louis, Missouri, to a family with deep roots in Chinese academia and scholarship. His father, Ju-Chin Chu, was a chemical engineering professor, and the Chu family placed a strong emphasis on education and intellectual achievement. Chu grew up in a household where academic accomplishment was the norm; multiple members of his extended family earned advanced degrees in science and engineering.

Chu has spoken publicly about his upbringing in a Chinese-American family where scholarly pursuits were expected and celebrated. The family's intellectual tradition spanned generations, with numerous relatives holding doctoral degrees and pursuing careers in research and academia. This environment cultivated Chu's early interest in the sciences and set the stage for his later accomplishments in physics. Growing up in the United States as a second-generation Chinese American, Chu navigated between his family's cultural heritage and American academic life, a background that would later inform his perspective on international scientific collaboration and policy.

Education

Chu pursued his undergraduate studies at the University of Rochester, where he earned both a Bachelor of Arts and a Bachelor of Science degree. He then enrolled at the University of California, Berkeley, for graduate study in physics, completing both a Master of Science and a Doctor of Philosophy degree. His doctoral dissertation, completed in 1976, was titled "Observation of the Forbidden Magnetic Dipole Transition 6²P₁/₂→7²P₁/₂ in Atomic Thallium" and was supervised by Eugene D. Commins, a distinguished professor of physics at Berkeley known for his work in atomic and particle physics. The research involved precision spectroscopy of atomic thallium and contributed to the broader study of forbidden electromagnetic transitions in heavy atoms, a subject of interest in both atomic physics and tests of fundamental symmetries.

Career

Bell Laboratories

After completing his doctoral studies at Berkeley, Chu joined Bell Laboratories in Holmdel, New Jersey, one of the premier industrial research laboratories in the world during the latter half of the 20th century. It was at Bell Labs that Chu conducted the groundbreaking research on the cooling and trapping of atoms using laser light that would ultimately earn him the Nobel Prize in Physics. His work focused on using precisely tuned laser beams to slow the motion of atoms, effectively cooling them to temperatures only fractions of a degree above absolute zero. This technique, known as laser cooling, opened entirely new avenues of research in atomic physics, enabling scientists to study quantum phenomena with unprecedented precision. The development of optical traps and the ability to manipulate individual atoms had far-reaching implications for fields including precision measurement, quantum computing, and fundamental tests of physical theories.

Stanford University (First Tenure)

Chu left Bell Laboratories to join the faculty of Stanford University, where he continued his research into atom trapping and cooling. At Stanford, he expanded the scope of his work to include applications of laser-based techniques to the study of biological systems and polymers. In his research on polymers, Chu used optical methods to observe and manipulate individual polymer molecules, providing direct experimental evidence for theoretical models of polymer dynamics that had previously been tested only indirectly. This work represented an early example of the application of single-molecule techniques to soft condensed matter physics, bridging the gap between atomic physics and materials science.

Nobel Prize in Physics (1997)

In 1997, Chu was awarded the Nobel Prize in Physics, which he shared with French physicist Claude Cohen-Tannoudji and American physicist William Daniel Phillips. The Royal Swedish Academy of Sciences recognized the three scientists for their independent development of methods to cool and trap atoms with laser light. Chu's contribution centered on the development of optical molasses and magneto-optical traps, techniques that used the momentum transfer from photons to slow atoms to extremely low velocities. The Nobel Committee noted that these methods had opened new domains of research and had practical implications for the development of highly accurate atomic clocks and for studies of Bose-Einstein condensates and other quantum phenomena.

Lawrence Berkeley National Laboratory

In October 2004, Chu was appointed director of the Lawrence Berkeley National Laboratory (LBNL), a U.S. Department of Energy national laboratory managed by the University of California. Concurrently, he served as a professor of physics and molecular and cellular biology at the University of California, Berkeley.

At LBNL, Chu shifted the laboratory's research agenda to place a greater emphasis on energy science, particularly on the development of renewable energy technologies and the study of climate change. He led efforts to establish new programs in solar energy conversion and biofuels research, drawing on the laboratory's expertise in materials science, chemistry, and biology. Chu sought to bring together researchers from different disciplines to address the energy challenges facing the United States and the world, advocating for large-scale investment in basic and applied energy research.

During his tenure at LBNL, Chu became increasingly prominent as a public voice on energy and climate policy. He argued that climate change posed a grave threat and that a concerted scientific and technological effort—comparable to the Manhattan Project or the Apollo program—was necessary to develop viable alternatives to fossil fuels. His advocacy and leadership at LBNL brought him to national attention and positioned him as a candidate for government service.

U.S. Secretary of Energy (2009–2013)

On January 21, 2009, Chu was sworn in as the 12th United States Secretary of Energy in the administration of President Barack Obama, succeeding Samuel Bodman. His appointment was historic, as he became the first Nobel Prize–winning scientist to serve in any presidential cabinet. His deputy secretary was Daniel Poneman.

As Secretary of Energy, Chu oversaw the Department of Energy's broad portfolio, which included the national laboratories, nuclear weapons stewardship, energy research and development, and implementation of portions of the American Recovery and Reinvestment Act of 2009, which directed substantial funding toward clean energy projects. Chu advocated for increased investment in renewable energy technologies, energy efficiency, and advanced vehicle technologies. He also promoted research into carbon capture and storage and supported the development of nuclear energy as a low-carbon source of electricity.

Chu was a prominent figure in the Obama administration's response to the Deepwater Horizon oil spill in 2010, where he assembled a team of scientists and engineers to help devise technical solutions to cap the well. His involvement in the crisis brought attention to the potential role of scientific expertise in addressing major environmental disasters.

During his tenure, Chu spoke frequently about the urgency of addressing climate change. In a widely cited interview, he warned that global warming could have catastrophic consequences for agriculture and water supplies, particularly in California and other parts of the American West. He also championed research into natural gas extraction methods, pledging to chart a path for safe drilling practices.

Chu resigned as Secretary of Energy on April 22, 2013, and was succeeded by Ernest Moniz.

Return to Stanford University

Following his departure from government service, Chu returned to Stanford University as Professor of Physics, Molecular & Cellular Physiology, and Energy Science and Engineering. At Stanford, he resumed his research activities, focusing on biological systems at the single-molecule level and on energy science. He has continued to publish research and to participate in scientific advisory roles.

Chu has also maintained an active public profile as a commentator on energy and climate policy. He has conceived of a "global glucose economy," a form of low-carbon economy in which glucose derived from tropical plants would be shipped globally in a manner analogous to petroleum, providing a renewable feedstock for energy and chemical production. This concept reflects his broader advocacy for innovative approaches to decarbonizing the global economy.

Continued Advocacy and Public Engagement

In the years following his government service, Chu has become one of the most prominent scientific voices calling for urgent action on climate change. He has delivered lectures at universities and institutions around the world, warning of the severe consequences of inaction and outlining technological pathways toward achieving net-zero greenhouse gas emissions.

In March 2025, Chu spoke at Northwestern University about the challenges of achieving net-zero emissions, addressing the growing global demand for energy, water, and food as the world population is projected to reach 11 billion by 2100.

In September 2025, Chu delivered a lecture at the Massachusetts Institute of Technology titled "The Challenges in Getting to Net-Zero GHG Emissions," in which he discussed both the technological and policy dimensions of decarbonization. That same month, he delivered a lecture at Harvard University, warning that the world faces a "Titanic" climate challenge and calling for a decisive shift away from fossil fuels.

In December 2025, Chu spoke at the National University of Singapore, reiterating his warnings about the climate crisis and calling for stronger international commitment to emissions reduction.

Chu has also been vocal about the importance of maintaining strong research universities in the United States. In July 2025, he warned that cuts to higher education and scientific research funding could allow China to surpass the United States in scientific capability, arguing that American universities are a critical competitive advantage.

In addition, Chu has written on nuclear energy policy, co-authoring a piece in Foreign Affairs in 2025 concerning Taiwan's energy security and arguing for the resumption of nuclear power on the island as a matter of strategic and environmental necessity.

In September 2025, Chu joined the External Advisory Board of the Tsinghua-Berkeley Shenzhen Institute (TBSI), reflecting his continued involvement in international academic collaboration.

Personal Life

Steven Chu has two children. He has spoken publicly about his Chinese-American heritage and the role his family's emphasis on education played in shaping his career. Chu has been recognized by the Chinese-American community and has visited China on multiple occasions in both official and academic capacities.

Chu is known for his ability to communicate complex scientific ideas to general audiences. He has delivered commencement addresses at multiple major universities, including Boston University in 2007 and Yale University in 2010.

Recognition

Steven Chu's most prominent honor is the 1997 Nobel Prize in Physics, shared with Claude Cohen-Tannoudji and William Daniel Phillips, for the development of methods to cool and trap atoms with laser light.

In 2009, Chu received an honorary degree from Harvard University, recognizing his contributions to physics and public service. He also received an honorary degree from Washington University in St. Louis, his birthplace city.

Chu served a one-year term as President of the American Association for the Advancement of Science (AAAS), beginning in February 2019. The AAAS is the world's largest general scientific society and publisher of the journal Science.

He has been a member of the National Academy of Sciences, the American Academy of Arts and Sciences, and the American Philosophical Society, among other professional organizations.

Chu has been the subject of media profiles in outlets ranging from The Chronicle of Higher Education to ABC News, where his appointment as Energy Secretary was covered extensively.

Legacy

Steven Chu's career has spanned fundamental physics research, university leadership, government service, and public advocacy for science-based policy on energy and climate. His Nobel Prize–winning work on laser cooling and trapping of atoms contributed foundational techniques that have become standard tools in experimental physics, enabling advances in atomic clocks, quantum information science, and tests of fundamental physical theories.

As director of the Lawrence Berkeley National Laboratory, Chu helped redirect a major national laboratory toward energy research, establishing programs in solar energy, biofuels, and energy efficiency that influenced the broader landscape of U.S. energy research. His appointment as Secretary of Energy marked a significant moment in the relationship between science and government, demonstrating the potential for direct involvement of leading scientists in policymaking at the highest levels.

Chu's continued public engagement on climate change and energy policy, including his lectures at Harvard, MIT, Northwestern, and the National University of Singapore, reflects his commitment to using his platform to communicate the urgency of the climate crisis and to advocate for evidence-based solutions. His concept of a "global glucose economy" and his advocacy for nuclear energy as part of the low-carbon energy mix have contributed to ongoing debates about pathways toward decarbonization.

His warnings about the need to protect American research universities and scientific infrastructure, particularly in the context of international competition with China, have added a dimension to public discourse about the role of science in national competitiveness and security.