Light into a controllable laboratory for quantum matter
At the University of Ottawa, researchers have found a way to use shaped light as a stand-in for the hidden world of electrons in matter — reprogramming the behavior of photons the way one might rewrite a score of music rather than rebuild an orchestra. By sculpting beams of light through programmable optical screens, the team has made visible what solid-state physics has long kept obscured: the delicate, topology-protected dynamics that govern exotic materials. It is a reminder that some of nature's deepest truths become legible only when we find the right medium through which to read them.
- Understanding how electrons navigate complex materials has long demanded hardware so unwieldy that each new experiment risks becoming its own engineering crisis.
- The University of Ottawa team cut through that complexity by replacing electronic circuits with three programmable optical screens that reshape light itself into a stand-in for quantum matter.
- Running more than 300 distinct quantum processes, the simulator reproduced the elusive signatures of topological materials — exotic phases once considered nearly impossible to observe directly — and projected their dynamics live onto a camera.
- The platform bent further still, simulating particle motion across cylinders, loops, and torus-shaped surfaces that photonic experiments have rarely, if ever, managed to replicate.
- The entire apparatus sits on a single reconfigurable tabletop and can be switched between hundreds of material configurations with a software update, no optics touched.
- The work now points toward compact photonic platforms capable of prototyping quantum technologies and illuminating quantum transport phenomena that solid-state devices keep stubbornly out of sight.
Imagine trying to decode how electrons behave inside a crystal by building a circuit large enough to hold all that complexity — then imagine replacing the whole apparatus with a reprogrammable beam of light. That is the leap researchers at the University of Ottawa and its Nexus for Quantum Technologies Institute, working with collaborators from Federico II University in Italy, have now made real.
The team built a programmable quantum simulator using three spatial light modulators — programmable optical screens — to sculpt both the shape and polarization of photons. Those photons then evolve precisely as electrons would inside a crystal. Professor Ebrahim Karimi describes it as tuning an instrument: each new configuration sends photons walking through a different virtual material, and switching between hundreds of them requires nothing more than a software update.
Testing the platform with both classical laser light and individual photons across more than 300 distinct quantum processes, the researchers achieved something particularly striking: they reproduced the signatures of topological materials, exotic phases whose internal geometry shields electrons from disturbance and whose direct observation has long been notoriously difficult. Senior research associate Alessio D'Errico notes that their optical setup lets those effects unfold in real time, visible directly on a camera.
The system's geometric reach proved equally remarkable. By reprogramming the optical patterns, the same tabletop setup simulated particle motion on closed loops, cylinders, and doughnut-shaped surfaces — geometries that encode real quantum physics and have rarely been achieved in purely photonic experiments. Because the quantum information lives in light rather than buried inside solid-state devices, every stage of the evolution can be photographed, offering an unusually clear view of dynamics that materials science typically keeps hidden.
Karimi frames the achievement plainly: the team has turned light into a controllable laboratory for quantum matter, one where complex dynamics can be designed, watched, and understood with a clarity that simply did not exist before. The findings appear across two 2026 publications, in Nature's Light: Science & Applications and in Advanced Photonics.
Imagine trying to understand how electrons behave inside a crystal by building an electronic circuit large enough to contain all the complexity. Now imagine doing the same thing with light instead—and being able to reprogram the entire experiment with a software update. That's what researchers at the University of Ottawa and its Nexus for Quantum Technologies Institute have accomplished, working alongside collaborators from Federico II University in Italy.
The team built a programmable quantum simulator that uses shaped beams of light to mimic how particles move through materials. Rather than constructing intricate wiring and hardware that grows more unwieldy with each new experiment, they use three programmable optical screens—called spatial light modulators—to sculpt both the spatial pattern and polarization of photons. The photons then evolve in the same way electrons would inside a crystal. Ebrahim Karimi, a full professor in the Department of Physics at the University of Ottawa, describes the approach with an apt metaphor: "We program the structure of light the way a musician tunes an instrument. Each configuration lets photons walk through a different virtual material, and we can switch between hundreds of them without touching the optics."
The researchers tested their platform with both classical laser light and individual photons, running more than 300 distinct quantum processes. A single input beam spread across thousands of output channels. In one critical validation, the simulator reproduced the signatures of topological materials—exotic phases of matter whose internal geometry protects electrons from disturbances, a phenomenon that could underpin next-generation electronics. Dr. Alessio D'Errico, a senior research associate on Karimi's team, notes that measuring these effects directly has always been notoriously difficult. "Our optical platform lets us watch those effects unfold in real time, right on a camera," he says.
What makes the system particularly powerful is its geometric flexibility. By reprogramming the optical patterns, the same setup can simulate particle motion on closed loops, cylinders, and doughnut-shaped surfaces—geometries that capture features of advanced quantum materials. These shapes have rarely, if ever, been reproduced in a purely photonic experiment. D'Errico emphasizes that these abstract geometries encode real physics: "Being able to explore them all on a single, reconfigurable table-top setup is a genuine step forward for quantum simulation."
Because the quantum information lives in light rather than in solid-state devices, every stage of the quantum evolution can be photographed directly. This gives researchers an unusually clear window into dynamics that are typically hidden deep inside materials. The work opens a path toward using compact photonic platforms to study quantum transport, probe topological phenomena, and prototype building blocks for future quantum technologies. Karimi sums up the achievement: "We've essentially turned light into a controllable laboratory for quantum matter studies. Complex dynamics can be designed, watched, and understood with a clarity that simply wasn't available before."
The findings appear in two 2026 publications. The first, "Compact and programmable large-scale optical processor in free space," was published in Nature's Light: Science & Applications, with authors including Maria Gorizia Ammendola, Nazanin Dehghan, Lukas Scarfe, Alessio D'Errico, Francesco Di Colandrea, Ebrahim Karimi, and Filippo Cardano. The second, "Programmable photonic quantum walks on lattices with cyclic, toroidal, and cylindrical topology," appeared in Advanced Photonics, authored by Alessio D'Errico, Nazanin Dehghan, Maria Gorizia Ammendola, Lukas Scarfe, Roohollah Ghobadi, Francesco Di Colandrea, Filippo Cardano, and Ebrahim Karimi.
Notable Quotes
We program the structure of light the way a musician tunes an instrument. Each configuration lets photons walk through a different virtual material, and we can switch between hundreds of them without touching the optics.— Ebrahim Karimi, Full Professor, University of Ottawa Department of Physics
Our optical platform lets us watch those effects unfold in real time, right on a camera.— Dr. Alessio D'Errico, senior research associate
The Hearth Conversation Another angle on the story
Why does it matter that you can reprogram this with software instead of rewiring hardware each time?
Because hardware changes take weeks or months. With optical screens, you upload new code and you're running a different experiment in minutes. That speed lets you explore hundreds of configurations instead of a handful.
So you're using light as a stand-in for electrons. Why would electrons cooperate with that substitution?
Electrons and photons follow the same quantum rules in certain ways. If you shape the light's path and polarization correctly, the photons evolve mathematically identical to how electrons would move through a crystal. It's not a metaphor—it's a direct translation.
You mentioned watching the dynamics on a camera. What can you actually see?
The light patterns themselves. Where photons end up, how they spread, how they interfere. In a solid crystal, those same dynamics are invisible—buried inside the material. Here, every quantum step is visible.
The torus and cylinder geometries sound exotic. Why would anyone care about those shapes?
Because real quantum materials have those topologies built into their atomic structure. By simulating them optically, we can understand how topology protects electrons from disorder—something that could make future electronics more robust.
What's the practical endpoint here? Are you building a quantum computer?
Not directly. We're building a tool to understand quantum systems before we try to engineer them. Think of it as a laboratory for exploring the physics that quantum technologies will eventually rely on.