Simulating quantum chaos: how Trinity researchers are helping to push quantum computers beyond their limits

Posted on: 11 February 2026

These are some of the questions that quantum researchers are currently most interested in but – spoiler alert – quantum mechanics is difficult, and working with systems sufficiently complex to fall in to the domain of quantum chaos is no picnic either.

Yet the discipline is rapidly evolving, and researchers from Trinity are at the forefront of advancements.

In a recent paper published in Nature Physics, an international team showed that we can indeed extract meaningful, trustworthy information to learn about quantum chaos—provided quantum computers are paired with powerful classical computational methods.

The work demonstrates that modern quantum processors, when combined with sophisticated error-mitigation techniques, can compete with the best available classical simulations in studying the dynamics of chaotic quantum systems. This is known as the quantum utility era and is currently where we sit as we push towards solving problems of commercial value.

The breakthrough is a real Trinity story too—one that highlights how the Trinity Quantum Alliance (TQA), founded in 2023, is enabling deep collaboration between academia and industry, in this case Algorithmiq and IBM, to tackle some of the most challenging problems in quantum science.

Many of the most interesting systems in nature—from high-temperature superconductors to exotic phases of matter—are governed by many-body quantum dynamics. These are systems made of many interacting quantum particles whose collective behaviour cannot be understood by studying each particle in isolation.

When such systems become chaotic, information spreads extremely rapidly, entanglement grows at the fastest possible rate, and classical simulation methods quickly fail. Even the world’s most powerful supercomputers struggle to track this behaviour due to the diverging complexity.

Ironically, this is exactly where quantum computers should shine. Because they obey the same laws of quantum mechanics as the systems they simulate, quantum processors are in principle perfectly suited to studying quantum dynamics. The catch is “noise”: today’s quantum computers are still imperfect, and errors accumulate quickly as circuits grow larger.

Here, the research team focused on a special class of quantum circuits known as dual-unitary circuits—systems that are maximally chaotic, yet mathematically tractable due to special space time symmetries. These circuits scramble quantum information as fast as physically allowed, earning them the nickname “rapid scramblers.”

What makes them special is that certain properties—such as how correlations decay over time—can be calculated exactly, even though the full dynamics are far beyond classical simulation. This makes them an ideal testbed: researchers know what the correct answer should be, even at scales no classical computer can reach.

In the experiments, quantum processors with up to 91 superconducting qubits were used to simulate these chaotic dynamics, pushing beyond the limits of brute-force classical methods.

To make this possible, the team relied on a cutting-edge method called tensor-network error mitigation (TEM), which is a product developed by the start-up Algorithmiq – a founding partner of the TQA. Instead of trying to physically correct errors on the quantum hardware, which requires full fault-tolerant quantum computers, TEM works by learning how noise propagates through a circuit and then mathematically undoing its effects during classical post-processing.

This approach allows researchers to recover accurate information without dramatically increasing experimental cost. As highlighted in a Nature Physics News & Views article accompanying the work, this combination of quantum computation and classical post-processing marks a major step forward for near-term quantum simulation.

From a Trinity perspective, this work is a flagship outcome of the Trinity Quantum Alliance, founded to bring together academic researchers and industrial partners around shared scientific goals in quantum computation, quantum information, and quantum simulation, building on Trinity’s world expertise as a pioneer in quantum education.

The Trinity contribution was led by John Goold, Professor of Physics at Trinity College Dublin and Director of the Trinity Quantum Alliance and founder of the Trinity MSc program, whose group has long worked at the interface of quantum thermodynamics, information theory, and non-equilibrium physics.

Two early-career researchers also played particularly central roles:

Matea Leahy, a former Microsoft Quantum scholarship holder, who is currently completing a joint PhD between Trinity and Algorithmiq. Her work on error mitigation and tensor-network methods with Algorithmiq was foundational to the success of the project.

And Nathan Keenan, who recently completed his PhD in Professor Goold’s group at Trinity, was the first graduate of the IBM–Trinity predoctoral programme. His contributions helped bridge theory, experiment, and large-scale quantum execution.

This combination of deep academic training and embedded industry collaboration is exactly the model the TQA was created to support. The project also exemplifies the Alliance’s international reach.

The collaboration involved Algorithmiq, whose team developed and implemented the TEM techniques used in the experiments. On the hardware side, the work relied on quantum processors and expertise from IBM, with teams spanning Dublin, Zurich, and New York. This global effort underscores how modern quantum research increasingly depends on tight integration between theory, software, and experimental platforms.

“Fully fault-tolerant quantum computers remains the ultimate long-term goal,” said Professor Goold. “But this work shows that useful, trustworthy quantum simulations are already possible today, provided we are clever about how we combine quantum hardware with classical computation methods.”

“For us the message is clear: by investing early in collaborative structures like the Trinity Quantum Alliance, Trinity has positioned itself at the heart of a rapidly evolving global quantum ecosystem. This paper is not just a scientific milestone—it is a demonstration of how academia and industry, working side by side, can extract real value from today’s quantum technologies and help shape the future of computation.”

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