Quantum memory stores information carried by particles like photons. This storage helps in several fields, such as long-distance quantum communication and photonic quantum computing.
Hollow-Core Light Cages Enable Scalable Quantum Memory on Chips
Quantum technology is shaping the future of communication and computing. One important part of that technology is quantum memory, a tool that can store tiny units of quantum information. Researchers have found new ways to build quantum memories, making them smaller and more flexible. A recent study reveals the use of hollow-core light cages (LCs) created right on a chip, marking significant progress toward powerful quantum systems.
Why Quantum Memory Matters
What Is Quantum Memory?
Quantum memory stores information carried by particles like photons. This storage helps in several fields, such as long-distance quantum communication and photonic quantum computing. For instance, when sending messages over long distances using photons, signals often weaken and get lost. Here, quantum repeaters equipped with quantum memories help by storing and synchronizing photons before forwarding them.
Challenges Until Now
Scientists used different methods to build quantum memories, including solid-state systems and cold atoms. Yet, these devices usually have bulky sizes or complex setups needing laser cooling. Some use hollow-core fibers (HCFs) to guide light through gases, but filling these fibers with atomic vapors takes weeks or months due to their tiny apertures.
This slow filling process creates delays and limits their usability in real-world applications.
The Breakthrough: Hollow-Core Light Cages on Chips
A Clever Design With Great Benefits
The research team chose hollow-core light cages (LCs) due to their unique features. Unlike traditional fibers that fill from the ends, light cages allow atomic vapor to enter through their sides quickly. This speeds up the filling process from months to just days.
Besides quick filling, light cages are very small and flexible in design. They can be 3D-nanoprinted onto silicon chips using two-photon polymerization, forming custom shapes that guide light effectively while protecting against chemical damage from cesium vapor inside the chip.
How the Experiment Worked
The team printed multiple light cages close together on one chip. Then they placed this chip inside a cell filled with cesium vapor heated to 74°C for better density. Two lasers created the signal and control beams, which together generated optical effects called electromagnetically induced transparency (EIT). This effect allowed photons to be stored temporarily within the cesium atoms inside each LC’s core.
The signal beam carried faint pulses simulating single photons, while a control beam managed their storage duration. After careful measurements, they found storage times around hundreds of nanoseconds, enough for many practical operations in current quantum devices.
Stable and Efficient Performance
The new light cage memories showed stable behavior during tests lasting over five years without degradation from exposure to reactive cesium atoms, thanks to protective coatings like alumina layers covering each structure’s surface.
This durability highlights an important future advantage: long-lasting photonic circuits that can perform advanced tasks in networks and computers without frequent replacements or repairs.
Looking Ahead: Impact on Quantum Technology
A Step Towards Spatial Multiplexing
A major milestone is achieved by integrating several independent light cage quantum memories on one chip simultaneously; they deliver consistent performance across devices without interference among channels.
This capability opens possibilities for spatial multiplexing, storing multiple photon states at once across different waveguides on the same microchip, which greatly enhances communication rates in quantum repeater nodes or complex photonic processors.
Paving the Way for Photonic Quantum Computers
Besides communications, controlling groups of synchronized photons is crucial for emerging types of photonic quantum computers using measurement-based methods requiring rapid photon storage followed by feed-forward actions within microsecond windows.
The flexibility of LCs printed directly onto chips complements ongoing efforts aimed at building scalable optical platforms combining high-bandwidth memory with integration ease unmatched by conventional fiber systems alone.
Additionally, to stay updated with the latest developments in STEM research, visit ENTECH Online. Basically, this is our digital magazine for science, technology, engineering, and mathematics. Further, at ENTECH Online, you’ll find a wealth of information.
Reference
- Gómez-López, E., Ritter, D., Kim, J., Kübler, H., Schmidt, M. A., & Benson, O. (2026). Light storage in light cages: a scalable platform for multiplexed quantum memories. Light Science & Applications, 15(1), 13. https://doi.org/10.1038/s41377-025-02085-5
- Author
- Latest Posts
I’m a web developer and science writer with a Master’s degree in Computer Applications (MCA) from Pune University.
I work in tech, building websites and staying updated with the latest developments. I also love writing about physics, chemistry, technology, robotics, mathematics, and breakthrough innovations. My passion is breaking down complex scientific topics into simple, easy-to-understand stories.
My goal is to help everyone stay informed about the exciting changes happening in science and technology. I believe understanding science shouldn’t be complicated—it should be accessible to all.
