In 2009, fresh from earning his doctorate, Tang Shibiao entered what was then a scientific "no man's land" — the industrialization of quantum technology in China.

Seventeen years later, Tang, now deputy chief engineer of QuantumCTek in Hefei, Anhui province, and his team have developed a palm-sized quantum communication device — a breakthrough once considered impossible.

The revolutionary device is easier to deploy, more stable and improves performance in securing information systems for the communications, financial and power sectors.

"Quantum-safe technology helps us better safeguard daily communications, from phone calls to file transfers," said 44-year-old Tang. "This technology is now being rolled into everyday life. The Quantum Secured Call product, for instance, has already reached over six million users."

Quantum communication distributes encryption keys based on the laws of physics. Any interception is immediately detectable by both communicating parties.

"It's like generating an envelope that only the sender and receiver can open," Tang added.

The secure communication is supported by extensive infrastructure. Tang said that China has built more than 12,000 kilometers of a national wide-area quantum-secure communication network, covering major cities such as Beijing, Shanghai, Hefei in Anhui province and Jinan in Shandong province.

"At the beginning, we were in an uncharted area. There was no road map," Tang said.

"In quantum communication, we modulate and detect signals of single photons, a task as challenging as catching a specific raindrop in a storm. To achieve this, single-photon detectors are essential parts of the quantum communication module."

At the outset these detectors were imported, including core components. They were costly and slow to arrive, and often underperformed.

"These constraints posed a major bottleneck for industrial expansion. If we don't master core technologies, advancing industries would be like trying to draw water from a dry well," Tang added.

It took Tang and his team years to achieve the initial breakthrough and realize basic domestic production of the detector, made possible through collaboration with leading domestic research institutions and industry partners.

The team's anxiety was real, as there was no domestic precedent for success, so they pored over research and consulted experts. The breakthrough came only after countless trials on materials and structures, accompanied by countless sleepless nights.

Early prototypes failed. "We'd press the power switch and the circuit component would burn out," Tang said. "We embraced trial and error from the start — a mindset we still uphold today. Since we were exploring uncharted territory globally, hesitation or shifting directions would have doomed the effort. Moving forward with persistence was our only path to success."

By the end of 2025, Tang and his team had successfully developed a mobile-phone-sized quantum communication module, reducing the size by more than 100-fold compared with the first-generation product.

lihongyang@chinadaily.com.cn