Infinite potential

In 2005, Xue was invited to work for the department of physics at Tsinghua University, and later that year he was selected to be an academician at the Chinese Academy of Sciences－as one of the youngest members at the age of 41.

Xue and his team started to research the quantum-anomalous Hall effect in October of 2008.

Four years later, on the night of Oct 12, 2012, Xue came home earlier than usual. At around 10:30 pm, after parking his car, he received a message from Chang Cuizu, a member of his experimental team, saying that the first sign of the quantum-anomalous Hall effect had been detected. The message was so important that Xue still keeps it on his phone.

Ma Xucun, a professor of physics at Tsinghua University, remembers Xue brought two bottles of champagne to the laboratory to celebrate with his team the next day.

"Our team has its own sense of unity, but we always collaborate with other teams, too," says Ma.

Ma knows that Xue cares about every aspect of his students' lives. He's a hard taskmaster when it comes to presenting every detail, even down to the format of an email.

Their discoveries were published in the journal Science in March 2013 and shocked the world. The quantum-anomalous Hall effect is a phenomenon that has puzzled the physics community for over 130 years, as its potential for creating electronics with reduced energy costs and heat emissions would allow engineers to create even more powerful supercomputers.

Chen-Ning Yang, a winner of the Nobel Prize for physics, said at a conference that Xue's research was groundbreaking in the field and worthy of a Nobel.

Xue says that while it may seem that his team spent only four years tackling the difficulties in identifying the quantum-anomalous Hall effect, they actually spent up to 30 years preparing for it.

"There are many other teams in the world that are researching this topic, such as teams from the University of Tokyo, the Massachusetts Institute of Technology and Stanford University. But it was first observed in a Chinese lab," says Xue.

Xue says that collaboration between his team members was one of the most important factors behind the breakthrough, and he regards this as one of the basic requirements for his students.

He once answered an email from a student asking what attributes he was looking for in potential research candidates. He replied that a strong interest in science and the ability to communicate with others were the key factors other than a solid academic background.

Wang Ruifeng, 25, became a student of Xue's in 2017. He listened to Xue's speech in Hefei, Anhui province, in his junior year and decided to study with him for his doctorate.

"He is amenable and talkative, but he is really tough when it comes down to research. On one occasion, when I just jotted down the references and page citations in one of my reports, the professor pointed out that I should also add the names of the original authors," Wang says.

In January, Xue and his team received the top prize in this year's National Natural Science Awards for the first experimental observations of the quantumanomalous Hall effect in 2012.

In the six years since their discovery, Xue's team has turned up the heat of their efforts by a factor of 10.

Today, this enthusiastic team continues to grow more samples and characterize them, even late into the night when it is very quiet, with the aim of making more valuable progress in the field of condensed-matter physics.

Xue and his team are also working on superconductivity. There is a periodic table of superconductivity on the wall of Xue's office, and he studies it once a day.

"As scientists, we should solidify our basic knowledge each day and always keep thinking. My theories could be proved wrong in the future, but it doesn't matter. Being a scientist means you have the duty to solve the unsolved and challenge the limits of what we know as human beings," says Xue.

"Scientists are as curious as children. I hope that in the future, scientists can break free of their boring image and instead be regarded as role models for the younger generations and attract more youth to enter into the world of science."