《自然》：潘建伟：Liàngzĭ zhī fù

PAN JIANWEI: Father of quantum

A physicist took quantum communication to space and back.

BY ELIZABETH GIBNEY

In China, some call him Liàngzĭ zhī fù: ‘Father of Quantum’. It’s an apt name for Pan Jianwei, widely hailed for leading China to the forefront of long-distance quantum communication: harnessing quantum laws to transmit information securely. After training in Europe, Pan returned full-time to China in 2008, and has since lit a fire under the country’s efforts in quantum technology. “It seems like a couple of times a year I’m shocked when I read about what they’re doing,” says Christopher Monroe, a quantum physicist at the University of Maryland in College Park.

In July, Pan and his team at the University of Science and Technology of China in Hefei reported that they had smashed the record for quantum teleportation, transmitting the quantum state of a photon on Earth 1,400 kilometres to a photon on an orbiting satellite. And in September, the team used that satellite to beam photons to Beijing and Vienna, generating quantum encryption keys that allowed teams in these cities to video-chat with complete security. Because detecting the photons disturbs their quantum states, would-be hackers cannot intercept the keys without their activities being noticed.

The demonstration was a “historic event”, says Anton Zeilinger, Pan’s former PhD adviser and his current collaborator at the University of Vienna. Pan’s group, he says, is surging ahead in the development of a quantum internet: a network of satellites and ground-based equipment that could share quantum information across the globe.

This would allow unbreakable worldwide encryption, as well as new experiments that harness long-distance quantum connections, such as combining light from detectors across the planet to create a super-resolution telescope. For now, Pan’s team has plans to launch a second satellite, and is running another quantum experiment in space aboard China’s Tiangong-2 space station. In the next five years, Pan says, “Many wonderful results will come. It’s really a new era.”

Although he leads a group of 50 scientists spanning multiple disciplines — including quantum simulation, computation and optics — Pan is the “essential brain” behind the work, says Zeilinger, bringing to it a combination of vision, organization and a flair for experiment.

Known as an optimist with unending enthusiasm, Pan also has a gift for persuading funders. And he is quietly confident that the Chinese government will support his next big plan: a US$2-billion, 5-year initiative focused on quantum communication, metrology and computation, which mirrors a $1.2-billion European flagship initiative announced in 2016.

Pan’s skill lies in picking the right problem and taking risks, says Monroe. “China is very lucky to have him.”