In a study published in npj Quantum Information, University of British Columbia researchers propose a solution to a major challenge in quantum networking: a device that can “translate” microwave signals to optical signals and vice versa.
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The device might function as a universal translator for quantum computers, allowing them to communicate across long distances and transforming up to 95% of a signal with very little noise. And it all fits on a silicon chip, the same material used in standard computers.
It's like finding a translator that gets nearly every word right, keeps the message intact and adds no background chatter.
Mohammad Khalifa, PhD, Study Author, Faculty of Applied Science, University of British Columbia
“Most importantly, this device preserves the quantum connections between distant particles and works in both directions. Without that, you'd just have expensive individual computers. With it, you get a true quantum network,” added Khalifa.
How it Works
Information is processed by quantum computers utilizing microwave signals. However, that data must be transformed into optical signals that can be transmitted over fiber optic cables to be sent across continents or cities. Due to their extreme fragility, these signals can be destroyed by even minor translation errors.
That poses a dilemma for entanglement, the phenomenon on which quantum computers rely, in which two particles remain connected regardless of distance. Einstein described it as “spooky action at a distance.” Losing that connection entails losing the quantum advantage. The UBC gadget might allow for long-distance quantum communication while maintaining these entangled links.
The Silicon Solution
The team's design is a microwave-optical photon converter that can be built on a silicon wafer. The breakthrough is found in tiny engineered imperfections, magnetic defects deliberately placed in silicon to regulate its characteristics. When microwave and optical signals are perfectly tuned, electrons in these defects change one signal to the other without absorbing energy, avoiding the instability that characterizes other transformation methods.
This device also operates efficiently at incredibly low power levels, just a millionth of a watt. The authors proposed a realistic design that includes superconducting components, which carry electricity precisely, as well as specifically engineered silicon.
What’s Next
While the work is still theoretical, it represents a significant advance in quantum networking.
We're not getting a quantum internet tomorrow—but this clears a major roadblock.
Dr. Joseph Salfi, Study Senior Author and Assistant Professor, Department of Electrical and Computer Engineering, University of British Columbia
“Currently, reliably sending quantum information between cities remains challenging. Our approach could change that: silicon-based converters could be built using existing chip fabrication technology and easily integrated into today’s communication infrastructure,” added Salfi.
Eventually, quantum networks might offer completely impenetrable internet security, indoor GPS, and the ability to solve issues that are currently out of reach, such as inventing new drugs or predicting the weather with substantially enhanced precision.
Journal Reference:
Khalifa, M., et al. (2025) Robust microwave-optical photon conversion using cavity modes strongly hybridized with a color center ensemble. npj Quantum Information. doi.org/10.1038/s41534-025-01055-4.