Paul Ching-Wu Chu: Co-discoverer of High-Temperature Superconductivity at Tc=93K, Breaking Through the Liquid-Nitrogen Temperature in 1987

30-second overview: Paul Ching-Wu Chu was born in Hunan in 1941. After graduating from the Department of Physics at National Cheng Kung University, he went to the United States and earned a PhD in physics from the University of California, San Diego.¹ In January 1987, his University of Houston team and Maw-Kuen Wu of the University of Alabama jointly discovered yttrium barium copper oxide (YBCO) with Tc=93K, crossing the liquid-nitrogen temperature threshold (77K) for the first time and opening the era of high-temperature superconductivity.² From July 2001 to 2009 he served as president of the Hong Kong University of Science and Technology.³ In March 2026, he published a new Tc=151K breakthrough in PNAS,⁴ and remains active in research at age 85.

1941: From Hunan to Taiwan

Paul Ching-Wu Chu was born in Hunan in 1941. As a child, he moved with his family to Taiwan and studied in the Department of Physics at National Cheng Kung University. After graduating, he went to the United States, first earning a master's degree at Fordham University and then entering the University of California, San Diego, where he received his PhD in physics.¹

In 1979, he formally became a professor in the Department of Physics at the University of Houston, where he built a superconductivity research team and began superconductivity research that has continued for nearly half a century.

The University of Houston was not among the most elite institutions in physics research at the time, but this choice gave Chu more room to establish his own research direction. He did not work within the established school frameworks of the most prestigious universities; instead, in a relatively free environment, he pushed superconductivity research toward temperature levels that no one had expected.

YBCO Tc=93K: A Simultaneous Breakthrough Crossing the Liquid-Nitrogen Threshold

In January 1987, Chu's University of Houston team discovered that yttrium barium copper oxide (YBCO) had a critical temperature of 93K, exceeding the boiling point of liquid nitrogen (77K) for the first time. Almost simultaneously, a University of Alabama team led by Maw-Kuen Wu achieved the same breakthrough: two teams conquered this threshold in parallel.²

The significance of this number lies in the fact that 77K is the temperature of liquid nitrogen. Liquid nitrogen is dozens of times cheaper than liquid helium, and Tc exceeding 77K meant that high-temperature superconducting materials could be cooled with liquid nitrogen, greatly reducing practical costs. This discovery triggered a "superconductivity fever" in physics, with laboratories around the world racing to follow up.

The result was published in Physical Review Letters and has been cited tens of thousands of times.²

Chu and Maw-Kuen Wu achieved this breakthrough almost simultaneously. Two independent teams reaching the same conclusion at nearly the same time is a classic case of "parallel discovery" in the history of science. It shows both that the solution to this problem had become "ripe" at that moment, and that competition can accelerate the logic of scientific breakthroughs.

The 1987 superconductivity breakthrough set off a wave of "superconductivity fever": The New York Times reported it on the front page, and the American Physical Society's annual meeting saw scenes the media called the "Woodstock of Physics," with hundreds of physicists waiting late into the night for reports of the latest experimental data. This social reaction showed one thing: at certain moments, scientific breakthroughs can pierce the academic world and enter the public imagination directly. High-temperature superconductivity was one such moment.

President of HKUST: July 2001 to 2009

On July 1, 2001, Chu took office as the third president of the Hong Kong University of Science and Technology, serving until 2009.³ During his tenure, he promoted development in the physical sciences and raised HKUST's standing in the international academic community. After stepping down, he returned to the University of Houston to continue his research.

The role of HKUST president shifted Chu from researcher to institution builder. During his tenure, he continued to strengthen HKUST's positioning as a research university, advancing physics, engineering, and business. This transition (from measuring critical temperatures in the laboratory to planning university strategy in an administrative office) was the most unusual transformation in his career. It also shows that his abilities were not limited to experimental design.

Tc=151K: A New PNAS Breakthrough in 2026

In March 2026, Chu published a paper in the Proceedings of the National Academy of Sciences (PNAS), reporting a superconducting critical temperature of Tc=151K in a new material.⁴ Although 151K is above the temperature of dry ice (195K) and still requires cooling, this breakthrough further expands the usable temperature range of superconducting materials.

The movement from Tc=93K in 1987 to 151K in 2026 shows that high-temperature superconductivity research has not yet reached its endpoint after 39 years. Every new Tc record reopens the question: "Is room-temperature superconductivity possible?" If room-temperature superconductors are realized, they will fundamentally change the infrastructure costs of power transmission, maglev transportation, quantum computing, and many other fields.

When this result was published, Chu was 85 years old and still leading a laboratory at the University of Houston.

Academic Identity and Honors

Chu is a member of the U.S. National Academy of Sciences and the American Academy of Arts and Sciences, and was elected an Academician of Academia Sinica in 1994.¹ He has published more than 700 academic papers and has long been regarded as a candidate for the Nobel Prize in Physics.

Those 700 papers span from the 1987 superconductivity breakthrough to the latest PNAS result in 2026. This combination of volume and duration is rare among experimental physicists. It represents not merely output, but the ability of one laboratory to remain at the frontier of the same problem, how to raise the critical temperature, for nearly half a century.

Chu has long been nominated by outside observers as a candidate for the Nobel Prize in Physics, but this candidacy is external speculation, not official confirmation. The 1987 Nobel Prize for high-temperature superconductivity was ultimately awarded that same year to Swiss physicists Bednorz and Müller, whose pioneering work discovered cuprate superconductors. Chu's YBCO breakthrough is seen as the key advance immediately afterward, but it did not receive equivalent recognition.

The year in which he received the U.S. National Medal of Science requires further confirmation. His confirmed academic honors include: Academician of Academia Sinica (1994), member of the U.S. National Academy of Sciences, and member of the American Academy of Arts and Sciences.

Common formulation -> more precise reading: Chu is often called the "father of high-temperature superconductivity," but this title needs precise positioning. He is the co-discoverer of YBCO Tc=93K, in parallel with Maw-Kuen Wu; Bednorz and Müller were the earlier pioneers of cuprate superconductivity. In this context, "father" refers to someone who crossed the practical threshold of liquid-nitrogen temperature, not to the inventor of the research direction of high-temperature superconductivity itself.

🎙️ Curator's note: The meaning of that number in January 1987 (93K) in the history of physics lies not in how high its absolute value was, but in the fact that it crossed a concrete application threshold. Tc > 77K = liquid nitrogen can be used = costs fall from "only top laboratories can do this" to "industrially feasible." This crossing changed the entire downstream imagination of superconductivity research.

Chu's presidency at HKUST (2001-2009) gave him, beyond his identity as a Taiwanese American physicist, another role as a builder of higher education in Asia. The coexistence of these two identities in him represents a typical trajectory of global mobility among Taiwanese science and engineering talent from the 1970s to the 2000s: foundational training in Taiwan, research in the United States, and institution building elsewhere in Asia.

That he was still publishing a PNAS paper in 2026 at age 85 is itself a statement about scientific vitality: superconductivity research has not ended, and neither has he.

From physics at National Cheng Kung University to the University of California, San Diego; from the University of Houston to HKUST, Chu's career path is a standard template for the global mobility of Taiwanese science and engineering talent. At the same time, because of that 93K in 1987, it became an exceptional case. His story shows that a standard path can lead to nonstandard results, provided that enough time is invested in the right problem.

From Hunan to Taiwan, from National Cheng Kung University to the University of California, San Diego, from the University of Houston to the Hong Kong University of Science and Technology and then to PNAS, Chu's career spans nearly half a century of superconductivity research: from Tc=93K to 151K, he has remained alongside that rising temperature curve.

There are 39 years between the 1987 breakthrough and the 2026 PNAS paper. Over those 39 years, superconductivity research went through repeated peaks and troughs, and many physicists who entered the field at the time moved on to other subjects; Chu did not. This long-term commitment to a single problem is one of his most distinctive qualities among physicists.

Further reading: Paul Ching-Wu Chu — Wikipedia ｜ ETHW: High-Temperature Superconductivity Milestone

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