Aalto Team Couples a Helium-3 Time Crystal to a Mechanical Oscillator, the First Link Between a Time Crystal and an External Device

Overview

Researchers at Aalto University have linked a time crystal to an external system for the first time, according to ScienceDaily. The team, led by Academy Research Fellow Jere Mäkinen of the Department of Applied Physics, converted a continuous time crystal made from magnons in a Helium-3 superfluid into what amounts to a cavity-optomechanics-like platform, opening a route to controlling and tuning a quantum state that, by definition, exists in motion without external energy input.

The result was published in Nature Communications under the title “Continuous time crystal coupled to a mechanical mode as a cavity-optomechanics-like platform,” with the DOI 10.1038/s41467-025-64673-8, as listed in the ScienceDaily journal reference.

What a Time Crystal Is

A time crystal is a quantum system whose state repeats in time rather than only in space. The concept was proposed in 2012 by Nobel Prize-winning physicist Frank Wilczek, who suggested that certain quantum systems could organize themselves into repeating patterns that continue indefinitely without needing energy from the outside, as reported by ScienceDaily. Experimentalists confirmed the existence of time crystals in 2016, per the same outlet.

The defining feature, and the reason a time crystal had until now resisted being coupled to anything else, is that observing or otherwise driving the system from the outside risks destroying its perpetual motion. As Mäkinen put it to Aalto University, “Perpetual motion is possible in the quantum realm so long as it is not disturbed by external energy input.”

The Experiment

To build the system, the Aalto group used radio waves to inject magnons — quasiparticles, or groups of particles behaving as if they were individual particles — into a Helium-3 superfluid cooled to temperatures near absolute zero, according to ScienceDaily. Once the radio-wave input was switched off, the magnons self-organized into a time crystal. SciTechDaily confirms the same setup: radio waves pumped magnons into helium-3 superfluid cooled near absolute zero.

That time crystal then continued its motion for an unusually long period, lasting up to 108 cycles or several minutes before fading to a level that could no longer be measured, per ScienceDaily. As it gradually weakened, the time crystal interacted with a nearby mechanical oscillator, and the nature of that interaction depended on the oscillator’s frequency and amplitude. The key methodological move was that the coupling was both controllable and reversible without immediately collapsing the time-crystal state.

Describing the result, Mäkinen told ScienceDaily: “That is why a time crystal had never before been connected to any external system. But we did just that and showed, also for the first time, that you can adjust the crystal’s properties using this method.”

Why Optomechanics

The team frames the achievement as a bridge between time-crystal physics and the well-developed field of cavity optomechanics, where light is coupled to mechanical motion in order to measure or control either side of the interaction. According to ScienceDaily, Mäkinen explained: “We showed that changes in the time crystal’s frequency are completely analogous to optomechanical phenomena widely known in physics. These are the same phenomena that are used, for example, in detecting gravitational waves at the Laser Interferometer Gravitational-Wave Observatory in the U.S.”

That analogy is more than rhetorical. The paper’s title — “Continuous time crystal coupled to a mechanical mode as a cavity-optomechanics-like platform” — explicitly positions the time-crystal-plus-oscillator combination as a new variant of an established class of experimental platform, per the journal reference listed by ScienceDaily.

What the Researchers Say It Could Enable

The Aalto group flags two potential applications. The first is quantum memory. As Mäkinen told ScienceDaily, “Time crystals last for orders of magnitude longer than the quantum systems currently used in quantum computing. The best-case scenario is that time crystals could power the memory systems of quantum computers to significantly improve them.” The second is precision sensing: the same quote points to use “as frequency combs which are employed in extremely high-sensitivity measurement devices as frequency references.”

Aalto University summarises the framing as a way to “increase quantum computational and sensing power.”

What Is Not Yet Established

The demonstration is a coupling experiment in a cryogenic Helium-3 platform, not a prototype quantum memory cell. The article reported by ScienceDaily explicitly notes that the time crystal’s signal eventually fades below the measurement floor, and that translating the platform into a higher-performance memory or sensor would require reducing energy loss and increasing the oscillator’s frequency, as Mäkinen indicated: “By reducing the energy loss and increasing the frequency of that mechanical oscillator our setup could be optimized to reach down near the border of the quantum realm.”

No benchmarked figures of merit — coherence times relative to specific qubit modalities, or sensitivity numbers relative to existing frequency-comb references — are disclosed in the materials released alongside publication. Whether the technique transfers off the Helium-3 platform, and on what timescale, is also not addressed by the sources cited here.

Where the Work Was Done

The experiment was carried out at the Low Temperature Laboratory, part of OtaNano, Finland’s national infrastructure for nano-, micro- and quantum technologies, with computational resources from the Aalto Science-IT project, according to ScienceDaily. The paper’s author list, per the same source, comprises J. T. Mäkinen, P. J. Heikkinen, S. Autti, V. V. Zavjalov, and V. B. Eltsov.