5 Minutes
A Time Crystal You Can See
Physicists at the University of Colorado Boulder have announced a landmark demonstration: a time crystal that can be observed directly with optical microscopy and, under controlled conditions, seen by the naked eye. The formation appears as rippling, neon-hued stripes and represents the first instance of a macroscopic time-crystalline pattern produced from a familiar soft-matter material, liquid crystals. The team says this visible time crystal could lead to practical advances in photonic devices, secure anti-counterfeiting labels, two-dimensional optical barcodes, and random-number generation for cryptography.
Scientific background: What is a time crystal?
Time crystals extend the idea of ordinary crystals into the temporal domain. Conventional crystals — diamond, salt or quartz — have atomic lattices that repeat in space. A time crystal exhibits a pattern that repeats in time: its internal structure oscillates with a stable, repeating period that does not mirror the driving rhythm of its environment. This persistent, out-of-equilibrium oscillation is described as breaking time-translation symmetry.
The concept was proposed theoretically by Frank Wilczek in 2012 and stirred debate about whether it violated thermodynamic principles. Experimental realizations began to appear in the mid-2010s, and researchers have since explored diverse implementations in quantum systems and driven materials. The Boulder team has now extended this family by making a time crystal observable in the visible spectrum using a room-temperature soft material, widening the range of accessible experiments and potential applications.
Experiment details: Liquid crystals, light, and rippling stripes
How the time crystal appears under a microscope. (Zhao and Smalyukh, Nat. Mater., 2025)
The new time crystal uses nematic liquid crystals — rod-shaped organic molecules that combine fluidity with long-range orientational order, the same class of materials used in LCD screens. The researchers confined a thin layer of liquid crystal between two glass plates coated with a photoresponsive dye. When the sample was illuminated with a patterned, time-varying light field, dye molecules reoriented (polarized) in response to the light, exerting mechanical and orientational forces on the surrounding liquid-crystal molecules.
Those forces introduced localized kinks and defects that interacted across the film in a nonlinear way. The interactions produced a repeating temporal pattern: the director field (the average molecular orientation) evolved in a sequence that returned to itself with a stable period. Critically, the oscillation persisted for hours and remained robust against modest fluctuations in ambient light and temperature, demonstrating the hallmarks needed to classify the state as a time crystal.
Under polarized optical microscopy the sample shows undulating bands of color that sweep across the layer — the neon stripes observers can track in real time. Because the structure modulates optical properties, it’s directly visible and could be engineered into devices that encode information in time-varying optical patterns.
Key discoveries and implications
The Boulder demonstration establishes several advances at once: a visible, room-temperature time crystal; a platform built from inexpensive soft materials; and a repeatable method to generate long-lived temporal order driven by light. These attributes make the system attractive for applied photonics as well as for fundamental studies of non-equilibrium phases of matter.
Potential near-term applications include anti-counterfeiting labels that reveal time-dependent optical signatures, optical random-number generators that leverage complex, deterministic-but-unpredictable dynamics, and two-dimensional optical barcodes that encode information in temporal patterns rather than static images. The authors also suggest the approach could inspire photonic space–time crystal generators for telecommunications, where controlled temporal modulation of refractive index is a valuable resource.
The work is documented in Nature Materials and leaves open many directions for follow-up: exploring different dyes and liquid-crystal chemistries, tuning oscillation periods, integrating with microelectronic addressing, and probing quantum versus classical limits of time-crystalline behavior.
Expert Insight
Dr. Elena Martínez, a condensed-matter physicist and science communicator, comments: "This experiment is important because it translates an abstract symmetry-breaking concept into something you can watch under a microscope. Using liquid crystals means the effect is accessible and tunable — a promising bridge between foundational physics and real-world optical technologies."
Her assessment highlights the dual value of the result: it clarifies fundamental mechanisms of temporal symmetry breaking while offering a practical materials platform for engineers and device designers.
Conclusion
The first visually observable time crystal produced from liquid crystals marks a significant step in both fundamental and applied physics. By making temporal order visible and robust at room temperature, the University of Colorado Boulder team has opened new experimental routes to study non-equilibrium phases and seeded potential technologies in photonics, anti-counterfeiting, and secure communications. Continued work will map how time-crystalline properties vary with material composition and driving protocols — and how those properties can be harnessed in devices.
Research source: Zhao and Smalyukh, Nature Materials (2025).
Comments