Researchers have managed to coax a quantum computer to pulse with a rhythm unlike any before—a rhythm that defies conventional physics. For the first time, scientists have transformed a quantum processor into a robust time crystal, a bizarre state of matter that ticks endlessly without external energy.
This achievement, the work of physicists from China and the United States, could mark a turning point for quantum computing. By stabilizing the delicate systems that underpin this cutting-edge technology, the experiment hints at a path toward practical quantum computers capable of solving problems far beyond the reach of traditional machines.
The Pendulum That Defies Physics
Unlike conventional phases, such as solids or liquids, time crystals exist in a state of perpetual motion. Let me explain.
Imagine holding a diamond in your hand. Its atoms are locked in a rigid, repeating lattice of carbon atoms—a perfect order that doesn’t change unless you break it. This is what defines most crystals: a static, stable arrangement of atoms in space.
Now, imagine a crystal that moves endlessly. Not in space, but in time. This is the essence of a time crystal—a structure that repeats itself not in the physical dimensions we’re used to, but across time.
In a time crystal, the atoms (or quantum bits, depending on the experiment) aren’t locked into place. Instead, they exist in a cycle of perpetual motion. Picture a lattice with an empty space where an atom shifts into the void. That movement creates a new vacancy, which is quickly filled by another atom, and so on, in a never-ending dance. It never stops. Crucially, this motion happens without any external energy input, defying the natural expectation that systems eventually wind down.
Time crystals are weird. They challenge our fundamental understanding of physics. They exist outside the realm of equilibrium, which is where most natural processes take place. They also seem to sidestep the second law of thermodynamics—the rule that says systems naturally move toward disorder over time.
First theorized in 2012 by Nobel laureate Frank Wilczek, time crystals were considered almost too bizarre to be real. But recent advances in quantum mechanics and experiments with superconducting qubits have shown they’re very much real. These systems oscillate predictably over time, creating what physicists call “discrete time-translation symmetry breaking.”
A Step Beyond Regular Time Crystals
Topological time crystals take this concept further. They don’t just rely on the repetitive motion of particles; their unique behavior is rooted in “topology,” a branch of mathematics that studies shapes and connections. This means their periodic behavior isn’t determined by any single particle or local interaction but by the system’s overall structure.
Here’s a simple analogy: imagine a spiderweb. A regular time crystal might behave like a single strand of the web vibrating rhythmically. But in a topological time crystal, the entire web is interconnected. If one part moves, the ripple affects the whole system. The result? The crystal’s time-repeating behavior is stronger, more stable, and resistant to disturbances, thanks to this deep, networked connection.
These properties are very appealing for quantum computers. These machines can process information in parallel with the potential to be orders of magnitude more powerful than today’s most advanced conventional computers. Quantum computers could revolutionize fields as diverse as drug discovery, weather prediction, and materials science. But with great potential comes significant challenges. Chief among them is error. As quantum computers scale up, the intricate entanglement of their qubits—quantum bits—makes them vulnerable to even the slightest environmental interference.
That’s where time crystals come in.
By inducing a stable form of time-crystal behavior in a superconducting quantum computer, the researchers demonstrated a way to make quantum systems more resilient. The oscillations in a time crystal are a collective property of the system, meaning they’re less affected by disturbances in individual qubits. By embedding this behavior into a quantum processor, the team created a system that maintained its stability even when exposed to simulated noise.
The team of researchers, spanning institutions from China’s Tsinghua University to Harvard University, engineered their experiment on an array of 18 superconducting qubits. These qubits, programmed into a two-dimensional lattice, were driven periodically using a complex quantum algorithm.
This periodic driving introduced a phenomenon called “discrete time-translation symmetry breaking.” However, unlike in previous time-crystal experiments, this breaking occurred only in nonlocal quantum operators—properties that are distributed across the entire qubit system.
To capture this effect, the scientists used a specialized model known as the Floquet surface code. This allowed them to program the qubits with unprecedented precision, achieving gate fidelities above 99.9%. With more than 2,300 single-qubit gates and 1,400 two-qubit gates executed in their circuits, they observed oscillations in the system lasting far longer than previously demonstrated.
Why Does This Matter?
This discovery pushes the boundaries of quantum mechanics. While time crystals are fascinating in themselves, the coupling of topological order with time translation symmetry breaking opens doors to studying entirely new phases of matter. The researchers noted that the observed oscillations were robust, surviving local perturbations—an essential trait for potential applications in quantum computing.
But while this work showcases the possibilities of modern quantum processors, the journey is far from over. These results were achieved in the so-called prethermal regime, a temporary state before thermalization disrupts the delicate balance of quantum interactions.
Scaling this experiment to larger systems will be critical to truly unlocking the potential of topological time crystals. Practical applications, such as fault-tolerant quantum computing, could benefit immensely from the stability and resilience inherent in topologically ordered states.
Whether in discovering life-saving drugs or cracking unbreakable codes, quantum computers—steady as a time crystal—might one day reshape our world.
In the meantime, the pendulum keeps swinging.
The findings appeared in the journal Nature Communications.
