Quantum devices are beginning to recreate pieces of particle physics that are extraordinarily difficult to calculate on ordinary computers.
Particle physics is usually associated with enormous machines. The Large Hadron Collider accelerates particles around a 27-kilometer ring before smashing them together. Neutrino experiments can involve detectors containing thousands of tons of material. Astronomers study the early universe by looking across billions of light-years. Many of the most fundamental questions in physics seem to demand either enormous energies, enormous instruments, or observations of environments that cannot possibly be reproduced on Earth.
A different approach is now emerging. Instead of recreating the actual energies of the early universe or producing every particle found inside a high-energy collision, physicists can construct another controllable quantum system whose behavior follows similar mathematical rules. Arrays of ultracold atoms, trapped ions, superconducting circuits, and other programmable quantum systems can act as quantum simulators, allowing researchers to investigate simplified versions of phenomena that occur in quantum field theories.
The goal is not to build a miniature universe in the literal sense. It is to build a physical system in which the important relationships between matter and fields can be reproduced, controlled, and measured. As these experiments become more sophisticated, the boundary between quantum computing and experimental particle physics is beginning to blur. A 2026 overview of the field describes quantum simulation of lattice gauge theories as a rapidly advancing route toward problems in particle and nuclear physics that become prohibitively difficult for classical computation, particularly dynamical and dense-matter problems.
The reason quantum simulators are useful comes from an idea Richard Feynman emphasized decades ago: quantum systems are often extremely difficult to simulate using classical machines because the amount of information needed to describe them can grow extraordinarily quickly. A classical computer has to represent the quantum system using ordinary bits, while a controllable quantum system already obeys the same underlying rules.
This creates an unusual form of scientific experiment. Researchers can take one quantum system that is relatively easy to manipulate and engineer it so that its behavior represents another quantum system that is much harder to access directly. The atoms in the laboratory are not pretending to be literal quarks or photons. Instead, researchers map the relevant states, interactions, and symmetries of a particle-physics model onto quantities the experimental platform can control.
The comparison is somewhat like using a wind tunnel to study an aircraft. A wind tunnel does not reproduce an entire flight across the Atlantic. It isolates important physical relationships and creates an environment where they can be examined repeatedly. Quantum simulation applies that philosophy to systems governed by quantum mechanics, except the simulator must reproduce quantum relationships rather than simply classical forces.
One of the main targets is gauge theory, the mathematical framework underlying the fundamental interactions described by the Standard Model. Electromagnetism is described by a gauge theory, and the strong interaction that binds quarks inside protons and neutrons is described by another, more complicated gauge theory called quantum chromodynamics. Gauge fields are therefore not an obscure corner of theoretical physics; they form much of the basic language through which modern particle physics describes forces.
Physicists have spent decades studying these theories using a technique known as lattice gauge theory, in which continuous space is represented by a discrete grid so that calculations become computationally manageable. Classical lattice calculations have produced enormously important results, but some situations remain particularly difficult. Real-time evolution, systems far from equilibrium, and matter at certain extreme densities can cause the computational requirements to grow beyond practical classical methods.
Quantum simulators offer a fundamentally different route because the lattice can become more than a mathematical approximation stored inside a classical computer. Researchers can encode parts of it into an actual quantum device and then allow the system itself to evolve.
A particularly fascinating phenomenon to simulate is confinement. Quarks behave very differently from familiar particles such as electrons. An isolated electron can move freely through space, but individual quarks are not normally found on their own. They are confined inside composite particles such as protons and neutrons.
One intuitive way to picture confinement is to imagine two quarks connected by a field that behaves somewhat like a stretched string. Attempting to pull the quarks farther apart stores increasing energy in that field. Eventually, instead of producing one isolated quark, the system can create additional particles and reorganize itself. This phenomenon, called string breaking, is an important example of strongly interacting quantum dynamics.
These processes can be challenging to follow directly in real time using conventional calculations. Quantum simulation provides a way to build simplified gauge theories in which researchers can initialize the system, watch its evolution, and measure how fields and matter respond. Recent work has pushed these simulations beyond the simplest one-dimensional models toward two-dimensional gauge theories, an important step because many significant field-theory phenomena only become fully meaningful as additional spatial dimensions are introduced.
Another phenomenon is particle creation from strong fields. Quantum field theory predicts that sufficiently intense electric fields can convert energy into particle-antiparticle pairs, an effect associated with physicist Julian Schwinger. Producing this phenomenon directly under ideal conditions requires electric fields that are extraordinarily difficult to generate, which makes it a natural candidate for simulation.
A recent cold-atom experiment took a different route. Researchers constructed a quantum simulator implementing a simplified gauge theory and adjusted an effective background field so that they could study the corresponding pair-production dynamics in a controllable regime. The experiment allowed them to investigate how changing the field affected particle creation without needing to generate the extreme electromagnetic conditions required for the direct high-energy process.
This captures one of the most powerful aspects of analogue quantum simulation. Researchers do not always need to reproduce nature's physical scale. They need to reproduce the relevant quantum rules. An ultracold atomic cloud occupying a laboratory table can therefore provide information about mathematical processes normally associated with tremendously powerful electric fields.
Quantum simulators can also explore what happens when complicated quantum systems begin to thermalize. When ordinary objects interact internally, their energy tends to spread until the system approaches thermal equilibrium. Understanding how this familiar behavior emerges from microscopic quantum mechanics becomes surprisingly difficult in isolated many-particle systems.
In 2025, researchers used a trapped-ion quantum computer to study the thermalization dynamics of a two-dimensional lattice gauge theory. Their experiment examined how entanglement evolved and found signatures associated with the onset of quantum chaos, illustrating how programmable quantum processors can probe dynamics that are difficult to capture from first principles using classical methods.
The connection reaches beyond laboratory physics. Similar questions about far-from-equilibrium quantum matter appear in models of the early universe and in the aftermath of energetic particle collisions. Understanding how a highly excited quantum system reorganizes and approaches equilibrium is therefore a problem shared by quantum information, statistical mechanics, cosmology, and nuclear physics.
Even the choice between a qubit and a qudit can matter for these simulations. Most quantum computing discussions describe a qubit as the basic unit of quantum information, with two computational states. Physical quantum systems such as trapped ions can contain many usable internal states, however, allowing researchers to encode information in higher-dimensional units called qudits.
Gauge fields are naturally capable of carrying more than two possible states, so compressing them into ordinary qubits can require substantial additional hardware and complicated circuits. A 2025 Nature Physics experiment instead used trapped-ion qudits to simulate a basic building block of two-dimensional quantum electrodynamics. The researchers were able to represent higher-dimensional gauge fields more directly, reducing the required register size and circuit complexity while studying matter, magnetic-field behavior, and pair-creation dynamics.
This is a useful reminder that quantum computers do not necessarily have to imitate classical computers at the level of their architecture. If the physical problem naturally contains many-dimensional objects, allowing the quantum hardware to use more than two states can sometimes provide a more direct representation of the physics.
The long-term ambition extends well beyond the simplified models that current devices can handle. The Standard Model contains non-Abelian gauge theories, dynamical fermions, several spatial dimensions, and enormous numbers of interacting degrees of freedom. Reproducing quantum chromodynamics at the level needed to answer major unsolved particle-physics questions remains far beyond present quantum hardware.
Current experiments should therefore not be confused with complete simulations of the Standard Model. A handful of trapped ions is not replacing the Large Hadron Collider, and an ultracold atomic lattice is not literally producing the same matter that filled the universe immediately after the Big Bang.
Instead, the significance lies in the direction of progress. Researchers have moved from proposing quantum simulations of gauge theories to experimentally realizing increasingly complex pieces of them. Recent work includes two-dimensional models, dynamical matter, pair creation, and nonequilibrium dynamics, while theoretical proposals are extending toward larger and more realistic systems.
This may eventually give particle physicists a third major way to investigate nature. Experiments such as colliders observe what real particles do. Classical supercomputers calculate what our theories predict. Quantum simulators could occupy the space between them, creating controllable quantum systems that physically reproduce selected parts of those theories.
That combination is especially powerful because a simulator can be manipulated in ways the universe cannot. Researchers can change interaction strengths, prepare unusual initial states, slow down dynamics, repeat the same experiment thousands of times, or explore parameter regimes that may be inaccessible in natural systems. The simulator becomes less like a calculator and more like an artificial piece of theoretical physics that can be placed on a laboratory table.
The earliest motivation for quantum computing was not necessarily cryptography, optimization, or artificial intelligence. Feynman's original insight was closely connected to physics itself: nature is quantum, and perhaps the most natural machine for understanding a complicated quantum system is another quantum system.
More than forty years later, that idea is beginning to look less like a thought experiment. Quantum processors are still nowhere near replacing the enormous classical computing infrastructure used in particle physics, but they are becoming experimental tools for studying phenomena that ordinary computers find especially difficult.
The future quantum laboratory may therefore look very different from the popular image of a machine built only to run algorithms. Some quantum devices may function as programmable pieces of nature, designed to recreate the rules governing particles, fields, and extreme forms of matter in environments where physicists can finally watch those rules unfold.
A quantum simulator does not need to contain an entire universe to teach us something about one. Sometimes, it only needs to reproduce the right laws.