An international team of physicists created a "supersolid" made entirely of light, advancing the study of condensed matter. Led by Dimitris Trypogeorgos and Daniele Sanvitto at the National Research Council (CNR) in Italy, the researchers detailed their achievement in a study published in the journal Nature, as reported by ANSA.
A supersolid is a phase of matter that combines two apparently opposite characteristics: the rigidity of a crystal and the ability of a superfluid to flow without friction, allowing it to flow around obstacles while maintaining internal organization. This state has intrigued scientists for decades.
"We actually made light into a solid. That's pretty awesome," said Dimitris Trypogeorgos, reflecting on the historical nature of the experiment, which advances previous work that created a fluid from photons, as reported by ANSA.
The research represents the first time a supersolid quantum state of matter was created using light since supersolids had only been generated with ultracold atoms. This opens new possibilities for the study of exotic quantum states of matter and could transform fields including measurement devices and materials development.
In their experiment, the team used a semiconductor called aluminum gallium arsenide instead of ultracold atoms to create the supersolid. When laser light struck the ridges of the aluminum gallium arsenide structure, it produced hybrid particles called polaritons, which are quasiparticles that are part light and part matter.
Due to the designed constraints of the ridges, these polaritons formed into a supersolid, marking the first production of a supersolid made of light. Creating this state wasn't easy, as proving their achievement was a challenge; no experiment had ever produced a supersolid using light before, making testing and evaluating the findings difficult.
To confirm they had created a true supersolid, the researchers measured the density of the polaritons, a challenging task as no one had previously managed to create and experimentally evaluate a supersolid made of light, as reported by American Military News. By observing the polaritons, the scientists determined that they showed a "distinct modulation," similar to crystallizing, while also displaying signs of coherence.
Daniele Sanvitto explained to Asriran that they had to measure with great precision enough properties of the trapped and transformed light to demonstrate that it was both a solid and a fluid without viscosity. The research team plans to continue investigating the structure of their newly created supersolid, focusing on engineering its crystalline structure for further study, and they aim to refine their approach to better control these supersolid light formations.
The supersolid state of matter could find future applications in quantum technologies, including use as coolants for quantum devices and in high-capacity batteries, as reported by ecoticias.com. The team suggests that because their supersolid is made of light, it may be more flexible and easier to manipulate than atomic supersolids, potentially facilitating its use in future technological applications. Researchers are enthusiastic about developing next-generation technologies through the use of this new matter form.
Alberto Bramati from Sorbonne University in France noted that the new experiment contributes to physicists' understanding of how quantum matter can change its state during a phase transition. Trypogeorgos stated that this discovery could change the way quantum properties of light are studied, offering deeper insights into light-matter interactions under extreme quantum conditions, and has the potential to change our comprehension of both light phenomena and their practical attributes.
The phenomenon of supersolids has intrigued scientists since it was theoretically proposed in the 1960s, with theoretical research continuing for decades and recent experimental results validating predictions. Previously, supersolids were produced only in Bose-Einstein condensates, formed when a gas of atoms is cooled to near absolute zero, and such materials were only available in controlled experiments with ultracold atoms.
Until now, supersolids required complex experimental conditions. This ability to create a supersolid without relying on ultracold atoms and extreme conditions represents a simplification in experimental procedures, potentially making this state of matter more accessible for further research.
"Sometimes it's magical to see in physics how changing language and perspective leads to new knowledge," reflected Trypogeorgos.
The scientists believe that light-based supersolids may be easier to work with than supersolids made using atoms. The team explains that by increasing the number of quasiparticles, more condensates form through parametric scattering, eventually creating the supersolid structure.
The article was written with the assistance of a news analysis system.