A team of researchers at the Light Publishing Center led by professionals from the Humboldt-Universität in Berlin, the Leibniz Institute of Photonic Technology, and the University of Stuttgart has unveiled a revolutionary chip-based quantum memory. Using 3D-nanoprinted structures called “light cages” that offer a scalable and highly reproducible way to store quantum information, the scientists have addressed one of the key bottlenecks in quantum communication and computing, reports Science Daily. Detailed in Light: Science & Applications, their work is a remarkable combination of advanced 3D printing and atomic physics.
Quantum memories are important for future quantum networks, where fragile quantum signals must travel long distances without being lost. “Quantum repeaters rely on memories that can store and release light on demand,” noted the researchers, enabling information to move across a network through entanglement rather than fading away.
The transformative approach is focused on hollow-core waveguides, or light cages, that tightly confine light while being open to atomic vapor. Unlike conventional hollow-core fibers, which can take months to fill with atoms, the open geometry allows cesium atoms to diffuse into the core in just a few days. “We created a guiding structure that allows quick diffusion of gases and fluids inside its core,” the team explained, while maintaining “excellent optical field confinement.”
The light cages are fabricated directly onto silicon chips with the help of two-photon polymerization lithography, a commercial 3D-nanoprinting technique capable of nanometer-scale precision.
Inside each light cage, incoming light pulses are converted into collective atomic excitations and then released by a control laser. During demonstrations, the system was able to store extremely weak light pulses containing only a few photons for several hundred nanoseconds, with the potential to reach much longer storage times.
The platform is highly practical as it can operate slightly above room temperature and without cryogenic cooling. 3D-nanoprinting with chip-scale integration looks like a breakthrough for large-scale quantum networks and photonic quantum computing.
