UH physicist breaks superconductivity record again

This story originally published on July 25, 2016. It has been updated and is being republished as part of our Chronicle 125 series.

Thousands of scientists crammed the hallways of the Hilton Hotel in New York, jockeying for a seat inside the ballroom. Televisions were set up for the unlucky who couldn't squeeze inside for the event, which would later be dubbed the "Woodstock of Physics."

It was March 1, 1987, and just a few weeks earlier a Houston scientist named Paul Chu had turned the world of physics upside down by announcing he had created a material -- a calculated mix of yttrium, barium, copper and oxygen -- that could conduct electricity with no resistance. And he had done it at the "high" temperature of 93 degrees Kelvin, breaking a barrier many in the science community weren't sure could be crossed.

Chu's discovery of a high-temperature superconductor promised to usher in a new age of electricity distribution and storage, transportation and computing.

And while a technological revolution never occurred, it did establish Chu as one of Houston's most prominent scientists and made the city an epicenter of superconductivity research that continues today under the goal of pushing the temperature threshold even higher.

"Based on our previous analyses, we can get to room temperature," Chu said. "The question is when and how? I'm not sure, but the possibility is getting close."

Almost 40 years after Chu's seminal paper on superconductivity was published, he remains bullish about the field, which continues to spin off new fields of research.

He teaches and continues to be a looming presence at the Texas Center for Superconductivity, which was established at the University of Houston not too long after Chu's discovery.

Today it employs more than 200 people, many of whom were drawn to Houston because of Chu's reputation as a pioneer in the field.

"One thing about Paul is he's a scientist who is still hard at work at being a scientist," said Allan Jacobson, the center's former executive director who holds the Robert A. Welch Chair of Science at the University of Houston. "He's not done."

Nothing is impossible in Houston

Born in Taiwan, Chu, then known as Ching Wu, grew up interested in science, drawn to anything that was electric or magnetic.

As a young boy, he would sift through the junkyards of Ching Shui, his hometown, looking for parts to build a radio and a small motor.

He came to the United States for his master's degree at Fordham University. After obtaining it in 1965, he earned his doctorate at the University of California, San Diego.

He arrived in Houston in 1979 to accept a job as a physics professor. "That was the boom time of Houston," he said, "and nothing seemed to be impossible in Houston."

What did seem impossible, however, was high-temperature superconductivity.

Superconductivity was discovered in 1911 by a Dutch scientist working with mercury he cooled with liquid helium.

Before 1987, the phenomenon only had been observed when material was chilled to near absolute zero, around 4 degrees Kelvin.

Pushing the temperature higher was the stuff of fantasy.

Nonetheless, it was pursued by an endless cadre of scientists.

In 1986, some IBM scientists in Germany announced they had created a ceramic compound that could be a superconductor at 35 degrees Kelvin. The discovery set off a race among scientists to reproduce the results and possibly come up with a better concoction.

Within a year, Chu unlocked the secrets of superconductivity on his own, creating a compound known as YBCO, which could function at an astonishing 93 degrees Kelvin.

Getting to that temperature meant the material could be cooled by cheap, abundant liquid nitrogen.

The physics world reacted with a collective gasp. Many predicted Chu's superconductor would quickly lead to the creation of better power lines, trains, motors and all sorts of electronic devices.

Weeks after his paper was published, the Houston Chronicle trumpeted a Nobel Prize for Physics was likely for Chu and his discovery could earn billions for UH.

The courting of Chu

"It was not a surprise to me," Chu said of the fallout of his discovery. "Because this whole thing was expected by people for decades since 1911 after its initial discovery. So all of a sudden we reached that stage. It was quite natural that everyone was excited about it."

Chu didn't win the Nobel -- that honor went to the two German scientists -- but he did pick up several other top science prizes and most of the publicity for superconductivity research. Consequently, there was a concerted effort among the nation's top academic institutions to pluck him from UH.

Hottest on his heels was the University of California at Berkeley. But his mentor, C.N. Yang, the first Chinese American to win the Nobel Prize for Physics, told him he could have a larger effect in the world of science if he stayed in Houston.

"At the time, people in Houston, the state of Texas, they're very nice to me," he said.

Indeed they were.

Moving with speed unheard of in today's political world, Texas legislators approved legislation that established the Texas Center for Superconductivity at UH, a place where Chu could continue pushing the temperature barrier for superconductors. He was appointed the center's first director and a cadre of the world's top physicists packed their bags and headed to Houston.

"A large number of our students have gone on to become leaders in the field as well as leaders in government and industry," said Jacobson. "Paul was instrumental in bringing many of them here."

In the years following Chu's breakthrough, he and other scientists made another discovery: creating superconductors at higher temperatures for commercial applications is a costly enterprise.

So now they are trying to do one of two things -- improve the material by raising the temperature at which superconductivity occurs, or improve the material's overall performance.

"But if you look at history, we raised the temperature from 35 to 93 degrees almost overnight," Chu said. "So why couldn't we repeat this?

(Chu left UH in 2001 to become president of the Hong Kong University of Science and Technology. He returned 2009 with a $2.8 million grant from the U.S. Air Force Office of Scientific Research to further his search for new superconducting materials.)

2026 update

Today, at age 84, Chu shows no signs of stopping.

In March 2026, Chu and his team officially shattered another record in the field, setting a new ambient-pressure superconductivity temperature of 151 Kelvin (about minus 122 degrees Celsius).

It's the highest transition temperature achieved without high pressure since superconductivity was discovered in 1911. The transition temperature is the point below which a material reaches superconductivity, meaning electricity can flow through it without resistance, according to a UH News report.

Chu and Liangzi Deng, UH assistant professor of physics and principal investigator at the center, used a pressure quenching technique to lock in superconducting properties after removing pressure, allowing the material to remain stable under normal conditions.

The advance moves researchers closer to the goal of room-temperature superconductivity, which could dramatically improve power grids, medical technologies, energy systems and advanced computing by enabling electricity to flow without resistance.

"Once we bring the material to ambient pressure, it becomes much more accessible for scientists to use well-developed instrumentation to investigate it and further develop technologies for ambient condition operations," Deng told UH News.

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