A groundbreaking discovery in the world of quantum physics has been made by a small international team of nanotechnologists, engineers, and physicists. Their research, published in the esteemed journal Nature, reveals a novel way to manipulate laser light into becoming a supersolid, a state of matter that has previously only been achieved with atoms. This achievement not only adds a new dimension to our understanding of supersolids but also offers exciting potential for future research and applications in quantum mechanics and materials science.
Supersolids are fascinating entities that exist exclusively within the quantum realm. Unlike ordinary solids, which have well-defined and rigid atomic structures, supersolids exhibit a unique combination of properties. These include both solid-like and fluid-like characteristics, making them a subject of significant interest in the field of condensed matter physics. Supersolids are often compared to crystals due to their atomic-level order, yet they differ by exhibiting zero viscosity, meaning they can flow without friction. The most well-known example of a supersolid comes from research using ultracold atoms, where the quantum mechanical effects become observable under extreme temperatures.
Traditionally, supersolids have been made using ultra-cold atoms, requiring environments close to absolute zero to achieve the desired quantum effects. These cold environments allow for the formation of crystal-like structures in which atoms are arranged in a manner reminiscent of salt crystals. The ability to manipulate and observe such phenomena in this setting has provided deep insights into the strange behaviors of matter at quantum scales.
However, the team behind this new research has taken a daring step forward by creating a supersolid using light—a feat that had not been achieved before. One of the team members had previously contributed to a breakthrough over a decade ago, demonstrating that light could behave as a fluid under specific conditions. This prior work laid the foundation for their new approach to manipulating light at the quantum level.
To create their light-based supersolid, the researchers focused a laser beam on a piece of gallium arsenide, a semiconducting material known for its unique optical properties. The gallium arsenide had been specially engineered with micro-ridges designed to manipulate the behavior of light at a very small scale. When the laser light interacted with the ridges on the material, the photons in the light were absorbed and transformed into polaritons. Polaritons are hybrid particles that arise from the interaction of light and matter, effectively combining properties of both photons (light particles) and excitations within the material (which are often electron-hole pairs).
What sets this experiment apart is the precise control the researchers had over these polaritons. The micro-ridges on the gallium arsenide material confined the polaritons in a manner that forced them into forming an ordered, crystal-like structure, effectively creating a supersolid. This was the crucial breakthrough, as the researchers were able to manipulate light in such a way that it exhibited the defining characteristics of a supersolid, despite the fact that the material involved was not composed of atoms.
Once the supersolid was formed, the next challenge was to confirm its unique properties. Testing a supersolid made from light posed difficulties, as no such material had ever been observed before. Supersolids are challenging to study, even when made from atoms, because of their dual nature—they must demonstrate both solid-like and fluid-like properties simultaneously. The team conducted a series of tests to ensure that their creation adhered to the fundamental characteristics of a supersolid, including the crucial feature of zero viscosity.
The results were promising. Their light-based supersolid exhibited both solid-like structure and the ability to flow without friction, indicating that it was indeed a supersolid. The lack of viscosity confirmed that the material could flow in a way that was fundamentally different from ordinary solids, supporting the conclusion that the researchers had successfully created a supersolid made of light.
This achievement opens up new avenues for research into supersolids and their potential applications. One of the key advantages of working with light-based supersolids is that they may be easier to manipulate than those made with atoms. Atoms require extremely cold temperatures and complex setups to create supersolid states, which limits their practical use. By contrast, light-based supersolids might be created and studied under more accessible conditions, potentially accelerating research in this area and allowing for more experiments in a wider range of environments.
The team plans to continue their work on light-based supersolids, with the goal of further understanding their structure and behavior. One of the main areas of interest is investigating how the properties of these light-based supersolids differ from those of their atomic counterparts. In particular, researchers are eager to explore how these materials can be manipulated and controlled at the quantum level, which could lead to new insights into quantum mechanics and novel applications in quantum computing and materials science.
Furthermore, light-based supersolids may have practical implications for technology. The ability to create and control such materials could lead to advancements in areas such as quantum information processing, photonic devices, and the development of new types of sensors. By studying the behavior of light in these extreme conditions, scientists may be able to unlock new principles of physics that could revolutionize the way we approach computing, communications, and even the fundamental understanding of matter itself.
More information: Dimitrios Trypogeorgos et al, Emerging supersolidity in photonic-crystal polariton condensates, Nature (2025). DOI: 10.1038/s41586-025-08616-9