# Light storage in light cages: a scalable platform for multiplexed quantum memories

## TL;DR

Researchers developed a scalable quantum memory platform using 3D-printed light cages to store light pulses efficiently in cesium vapor.

## Contribution

The work introduces 3D-nanoprinted hollow-core waveguides (light cages) for scalable, chip-integrated quantum memories with improved performance.

## Key findings

- Light cages enabled hundreds of nanoseconds of photon storage in cesium vapor.
- Multiple LC memories were integrated on a single chip with consistent performance.
- The platform shows potential for parallel single-photon synchronization in quantum computing.

## Abstract

Quantum memories are essential for photonic quantum technologies, enabling long-distance quantum communication and serving as delay units in quantum computing. Hot atomic vapors using electromagnetically induced transparency provide a simple platform with second-long photon storage capabilities. Light-guiding structures enhance performance, but current hollow-core fiber waveguides face significant limitations in filling time, physical size, fabrication versatility, and large-scale integration potential. In this work, we demonstrate the storage of attenuated coherent light pulses in a cesium (Cs) quantum memory based on a 3D-nanoprinted hollow-core waveguide, known as a light cage (LC), with several hundred nanoseconds of storage times. Leveraging the versatile fabrication process, we successfully integrated multiple LC memories onto a single chip within a Cs vapor cell, achieving consistent performance across all devices. We conducted a detailed investigation into storage efficiency, analyzing memory lifetime and bandwidth. These results represent a significant advancement toward spatially multiplexed quantum memories and have the potential to elevate memory integration to unprecedented levels. We anticipate applications in parallel single-photon synchronization for quantum repeater nodes and photonic quantum computing platforms.

We implement 3D-nanoprinted hollow-core waveguides—so-called light cages—as atomic vapor-based quantum memories. These structures significantly enhance light–matter interactions within a compact, chip-integrated platform, marking a step forward in scalable and versatile photonic quantum technologies.