A new breakthrough may help scientists solve some of the mysteries of the quantum realm.

For the first time, physicists have been able to measure the geometrical ‘shape’ a lone electron adopts as it moves through a solid. It’s an achievement that will unlock a whole new way of studying how crystalline solids behave on a quantum level.

“We’ve essentially developed a blueprint for obtaining some completely new information that couldn’t be obtained before,” says physicist Riccardo Comin of the Massachusetts Institute of Technology (MIT).

The University of Science and Technology of China has achieved a significant milestone in quantum memory research, addressing a long-standing challenge in integrated solid-state devices. The team, led by Chuan-Feng Li and Zong-Quan Zhou, has demonstrated an integrated spin-wave quantum memory capable of extended storage times and on-demand retrieval. This development marks a critical step toward scalable quantum networks.

Quantum memories play a pivotal role in enabling long-distance entanglement by linking short-distance connections, overcoming photon transmission losses. Rare-earth ions doped crystals have emerged as promising systems for quantum memory, with integrated solid-state devices showing particular potential. However, prior implementations were limited to optically excited states, which inherently restrict storage time and retrieval flexibility due to the short lifetime of these states.

The breakthrough lies in the implementation of spin-wave storage. This approach encodes photons into spin-wave excitations in ground states, vastly extending storage times to the spin coherence lifetime and enabling on-demand retrieval. Nevertheless, the challenge of separating single-photon signals from noise caused by strong control pulses has hindered progress in integrated structures — until now.