Researchers at Queen’s University have built a new kind of computer that uses light instead of electricity—and it works at room temperature, stays stable for hours, and runs incredibly fast.
The machine is designed to tackle some of the hardest problems in science and industry, from protein folding for drug discovery to complex logistics and cryptography challenges.
The research was recently published in the journal Nature.
The project is led by Bhavin Shastri, Canada Research Chair in Neuromorphic Photonic Computing.
Together with his graduate students and collaborators from McGill University, the team showed that powerful optimization machines do not need exotic materials or extreme conditions.
Instead, their system is built from familiar technology—lasers, fiber optics, and modulators—the same tools that already carry data across the internet.
At the heart of this breakthrough is a physics idea called the Ising model. For over a century, scientists have used this model to describe how tiny magnets interact, with each magnet pointing either up or down.
Finding the lowest-energy arrangement of these magnets turns out to be mathematically similar to solving difficult decision problems, where many choices are tightly connected and influence each other.
Rather than using physical magnets, the Queen’s system uses pulses of light. Each “spin” is represented by the presence or absence of a light pulse.
These pulses travel through a loop, interact with one another, and gradually settle into a pattern that represents a good solution to a complex problem. In simple terms, the light pulses exchange information until they reach a kind of agreement.
Why does this matter? Many everyday tasks hide enormous complexity. Planning delivery routes for packages, designing efficient supply chains, or finding promising drug molecules all involve choosing the best option from an astronomically large number of possibilities.
For even moderate-sized problems, checking every option would take longer than the age of the universe using conventional computers.
What sets the Queen’s machine apart is its practicality. It runs at room temperature, which means far lower energy use than systems that require extreme cooling. It also remains stable for hours, while many earlier optical systems only worked for milliseconds before breaking down.
Despite using just five basic components, the researchers achieved 256 interacting spins—an impressive result compared to far more expensive efforts elsewhere.
The team now aims to scale the system further, improve efficiency, and work with industry partners to test real-world applications. If successful, computers made of light could become powerful new tools for solving problems that today’s machines still struggle with.
