Physicists have taken a step that sounds like science fiction: they have coaxed light into behaving as a “supersolid,” a phase of matter that is at once rigid and frictionless. Instead of treating photons as weightless messengers that only travel in straight lines, the new experiments show that under the right conditions light can organize itself into a crystal-like pattern while still flowing like a perfect fluid. The result is a new quantum state that blurs the line between waves and matter and opens a fresh frontier for controlling light at its most fundamental level.
At the heart of the work is a carefully engineered semiconductor structure that forces light to hybridize with electrons, creating new entities that can condense into a single quantum state. By sculpting the landscape in which these hybrids move, researchers have made that condensate spontaneously form a repeating pattern in space without losing its ability to flow. That combination of crystalline order and frictionless motion is the defining signature of a supersolid and, for the first time, it has been realized using light itself.
What a supersolid really is
To understand why this result matters, I need to start with what physicists mean by a supersolid. In ordinary solids, atoms sit in a fixed lattice and resist deformation, while in ordinary liquids, particles move freely and can flow but do not hold a shape. A supersolid is a quantum phase in which both behaviors coexist: particles arrange themselves in a rigid, spatially ordered structure yet can also flow with zero viscosity, a property more familiar from superfluids like liquid helium. In the standard Background description, the same material simultaneously breaks the symmetry of empty space by forming a crystal and preserves the phase coherence that allows frictionless flow.
For decades, supersolidity was mostly a theoretical curiosity, with early proposals focusing on helium and ultracold atomic gases. Experiments eventually found hints of supersolid behavior in Bose–Einstein condensates of atoms arranged in optical lattices, but those systems still involved massive particles. The new work pushes the concept into the realm of light by using hybrid particles called polaritons that inherit properties from both photons and matter. In the reported experiments, these polaritons condense into a single quantum state that shows the hallmarks of a supersolid, extending the idea of a rigid yet flowing phase into a photonic setting.
How scientists turned light into a quantum crystal
The key to transforming light into something that behaves like a material is to trap it in a structure where it repeatedly interacts with electrons. In the new experiments, Researchers at Italy’s National Research Council, identified as the National Research Council (CNR), used a semiconductor microcavity patterned into a photonic crystal with a regular array of ridges. Within this device, photons from a laser couple strongly to electronic excitations in the semiconductor, forming polaritons that act as quasiparticles with an effective mass. According to reports on the photonic-crystal design, the periodic structure shapes how these polaritons move and how their energies depend on position.
By tuning the laser and the geometry of the ridges, the team created conditions where the polaritons condensed into a macroscopic quantum state that was not uniform but instead developed a repeating density pattern. The ridge pattern controlled how these quasiparticles moved and their energies, forming a supersolid in which the density modulated like a crystal while the phase of the condensate remained coherent across the sample. Descriptions of the experiment emphasize that the polariton condensate emerged in a landscape engineered by the photonic crystal, so the spatial order was not imposed from outside but arose spontaneously from the interplay of interactions and the periodic environment.
Inside the polariton playground
At the microscopic level, the supersolid of light is built from polaritons, which are hybrid particles formed when photons strongly couple to excitons in the semiconductor. These polaritons inherit the lightness and coherence of photons and the interactions of matter, which allows them to behave collectively. As the laser pumps the microcavity, polaritons accumulate and can undergo a phase transition into a condensate where many of them share the same quantum state. Reports on the experiment describe how Complex interactions between the light and the material eventually formed a type of hybrid particle called a polariton, and how the ridge pattern guided these polaritons into a supersolid configuration, as detailed in accounts of the light condensate.
What distinguishes this condensate from a more familiar superfluid is the emergence of a spatially modulated density that repeats across the device. The polaritons cluster into bright regions separated by darker gaps, forming a pattern reminiscent of a crystal lattice, yet the phase of the wavefunction remains locked across the entire structure. In technical terms, the system breaks continuous translational symmetry by forming a lattice while preserving long-range phase coherence, the dual requirement for supersolidity. Accounts of the work note that the researchers carefully tuned the pumping conditions and the geometry of the ridges so that the condensate naturally adopted this modulated state, as described in coverage of the quantum supersolid behavior.
Why a supersolid made of light matters
Creating a supersolid from light is not just a conceptual stunt, it gives physicists a new platform for exploring quantum phases that are difficult to realize in conventional materials. Because polaritons can be created and destroyed by adjusting the laser, and because the underlying photonic crystal can be fabricated with nanometer precision, the system offers a high degree of control over interactions, geometry, and dissipation. Analyses of the work argue that this control makes the supersolid state of light a promising testbed for studying nonequilibrium quantum matter and for simulating complex condensed-matter phenomena in a tunable setting, as highlighted in discussions of the new phase of light.
There are also more applied possibilities. A supersolid of light could underpin ultra-sensitive interferometers that exploit both the rigidity of a lattice and the coherence of a superfluid, potentially improving measurements of tiny forces or displacements. It could enable new kinds of optical circuits where information is carried by collective quantum states rather than individual photons, with the crystalline order providing built-in channels for flow. Commentaries on the experiment suggest that the ability to sculpt and move such supersolid patterns might feed into future photonic technologies, including quantum simulators and devices that route light in ways not possible with classical optics, as explored in coverage of the supersolid state of light.
From theory to experiment, and what comes next
The realization of a light-based supersolid builds on years of theoretical and experimental work on exotic quantum phases. Earlier proposals showed that supersolidity could arise in ultracold atoms arranged in optical lattices, and experiments eventually confirmed such states in carefully tuned Bose–Einstein condensates. The new photonic implementation extends those ideas into a driven, dissipative system where particles are constantly injected and lost, yet a stable supersolid still emerges. Reports on the Italian experiments describe how Researchers at Italy’s National Research Council, referred to as Researchers at Italy’s National Research Council (CNR), have, for the first time, transformed light into a solid-like state that can exhibit complex states of matter, as detailed in accounts of the CNR work.
The experiment is documented in the paper “Emerging Supersolidity in Photonic-crystal Polariton Condensates,” which appeared in Nature and lays out the theoretical framework and measurements that support the supersolid interpretation. Accounts of the publication note that the paper “Emerging Supersolidity in Photonic-crystal Polariton Condensates” appeared in Nature and that it details how the polariton condensate in the photonic crystal acquires both crystalline order and superfluid-like coherence, as summarized in descriptions of the Emerging Supersolidity study.
A new playground for quantum light
Beyond the core experiment, the supersolid of light has already sparked a wave of interpretation and commentary that underscores how unusual this phase is. Some accounts describe how Scientists Just Turned Light Into a system that is Both Solid and Liquid at The Same Time, emphasizing that the polariton condensate behaves like a crystal and a wave simultaneously, as reported in discussions of the Scientists Just Turned discovery. Others highlight that Physicists create supersolid state of light, blending properties of liquids and solids, stressing that the phase combines rigidity with flow in a way that defies classical intuition, as noted in analyses of the blending properties of the new state.
There is also growing interest in how this work fits into a broader shift toward engineering quantum phases in photonic systems. Commentaries describe how Scientists have created a new state of light using a laser and a semiconductor, framing the result as part of a trend in which light is treated as a medium that can host complex states of matter, as discussed in summaries of the new state of light. Other reports emphasize that Scientists have created a supersolid using light for the first time and that this quantum breakthrough shows such phases can also occur in photonic systems, as highlighted in coverage of the quantum breakthrough. One analysis even frames the result as part of a broader story in which Supersolid, Scientists, and Mar are linked in a narrative about how Supersolid phases are moving from theory into experiment, as reflected in discussions of the Supersolid development.
As these interpretations accumulate, they converge on a simple but profound point: by turning light into a supersolid, Researchers have shown that even something as familiar as a laser beam can host phases of matter that were once thought to belong only to exotic quantum materials. Accounts of the discovery note that Supersolid, Scientists, and Mar are central to understanding how this work challenges traditional notions in quantum mechanics and opens new avenues for photonic technologies, as reflected in discussions of the scientists create experiments. Another commentary points out that Scientists have created a new state of light using a laser and a semiconductor and that this discovery, published in Nature, challenges traditional notions in quantum mechanics and opens new avenues for photonic technologies, as summarized in descriptions of the Nature report. Finally, one analysis notes that Mar, Supersolid, and Scientists are part of a broader narrative in which Researchers turned light into supersolid, for the first time, a groundbreaking achievement that advances the field of condensed matter physics, as described in accounts of the Scientists who achieved the result.
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