Quantum memory milestone brings secure communications closer to reality

Quantum memory milestone brings secure communications closer to reality
by Riko Seibo
Tokyo, Japan (SPX) Jul 08, 2025

In a major breakthrough for next-generation communications, physicists at Nanjing University have successfully transferred quantum information from light into solid quantum memory-using devices compatible with today's telecom networks. This advance pushes quantum networks closer to real-world deployment by solving a key challenge in linking light-based signals with matter-based memory.

Led by Professor Xiao-Song Ma, the research team achieved quantum teleportation from photons at telecom wavelengths into a rare-earth crystal memory. The experiment not only exceeded the limits of classical systems but also used hardware already aligned with modern fiber-optic infrastructure, paving the way for scalable quantum networks.

Quantum teleportation enables the transfer of a quantum state-without moving any physical particles-between systems like light and matter. Unlike copying or measuring, teleportation preserves the delicate quantum information by avoiding any direct exposure of the state itself. "This process keeps the quantum state intact and unknown, which is critical for maintaining security and coherence," explained Ma.

The team's work builds on a previous achievement: storing quantum data in solid-state memory over long durations. Now, by successfully teleporting quantum states into that memory, they've advanced from simple storage to dynamic exchange-an essential step for realizing a quantum internet.

Key to the success was the use of erbium ions embedded in yttrium orthosilicate (YSO) crystals. Erbium is unique because it interacts with light at around 1.5 micrometers-the same wavelength used in telecom fiber. Combined with a silicon nitride chip that generated entangled photons, the researchers were able to perform high-fidelity teleportation into the solid-state memory.

"We confirmed that the results were far beyond what classical systems could ever achieve," said lead experimenters Yu-Yang An and Qian He. "That means the effect we observed can only be explained using the principles of quantum mechanics."

The experiment's precision passed rigorous statistical tests, beating classical benchmarks by more than seven standard deviations. These results underscore the feasibility of integrating quantum systems into current communication networks and represent a major stride toward ultra-secure, large-scale quantum communications.

Research Report:Quantum Teleportation from Telecom Photons to Erbium-Ion Ensembles