• Scientists have successfully transformed light into a “supersolid,” a quantum state of matter that exhibits both solid-like crystalline structure and frictionless liquid-like flow simultaneously. This marks the first time such a state has been created from light, a significant milestone in quantum physics.
• Supersolids are a quantum phenomenon where particles form a rigid, ordered structure while flowing without viscosity. This duality arises from particles occupying the lowest energy state, enabling frictionless movement.
• Researchers used a laser to create photons, which interacted with a gallium arsenide semiconductor to form “polaritons” (quasiparticles combining light and matter). These polaritons were manipulated into a supersolid state using a specific quantum state called a “bound state in the continuum” (BiC).
• Supersolids provide a unique platform to study quantum interactions without thermal noise, offering insights into fundamental forces. They also hold potential for applications in quantum computing, superconductors, frictionless lubricants and advanced light-emitting devices.
• This discovery bridges fundamental science and practical applications, validating decades of theoretical work and opening new avenues for exploring quantum phenomena. It represents a transformative step in understanding matter and energy, with potential for groundbreaking future technologies.

For the first time in history, scientists have transformed light into a “supersolid,” a bizarre state of matter that defies classical physics by behaving as both a solid and a liquid simultaneously. This groundbreaking achievement, detailed in a study published in Nature, marks a significant milestone in quantum physics and opens new avenues for understanding the fundamental nature of matter and energy.

What is a supersolid?

Supersolids are a quantum mechanical phenomenon where particles arrange themselves into a rigid, crystalline structure while simultaneously flowing like a frictionless liquid. This duality is made possible by the particles occupying the lowest possible energy state, allowing them to move freely without viscosity—a property that governs how easily a fluid flows.

Historically, supersolids were first theorized over 50 years ago, but experimental evidence remained elusive until the advent of ultracold atomic Bose-Einstein condensates (BECs) in the early 2000s. These BECs, cooled to temperatures near absolute zero, provided the first glimpses of supersolid behavior. However, creating supersolids from light—a form of energy rather than matter—was thought to be impossible until now.

How light became a solid

The key to this breakthrough lies in the creation of “polaritons,” quasiparticles formed by coupling photons (light particles) with excitons (electron-hole pairs in a semiconductor). In this experiment, researchers at Italy’s National Research Council (CNR) and the University of Pavia used a laser to generate photons, which were then directed onto a gallium arsenide semiconductor. The interaction between the photons and the semiconductor’s excitations produced polaritons, which were manipulated into a supersolid state.

“This work not only demonstrates the observation of a supersolid phase in a photonic platform but also opens the way to the exploration of quantum phases of matter in non-equilibrium systems,” says physicist Daniele Sanvitto of the CNR’s Institute of Nanotechnology.

The team achieved this by structuring the semiconductor to guide the polaritons into a specific quantum state known as a “bound state in the continuum” (BiC). This state allowed the polaritons to condense into a crystalline structure while maintaining their fluid-like properties.

Why this matters

Supersolids are more than just a scientific curiosity—they offer a unique window into the quantum world. By studying these exotic states, researchers can observe quantum interactions without the interference of thermal noise, providing insights into the fundamental forces that govern matter.

Moreover, this discovery has practical implications. Supersolids could revolutionize fields such as quantum computing, where frictionless flow and coherent quantum states are highly desirable. They could also lead to advancements in superconductors, frictionless lubricants and even new light-emitting devices.

“Realizing this exotic state of condensed matter in a fluid of light flowing in a semiconductor nanostructure will allow us to investigate its physical properties in a new and controlled way,” says condensed matter physicist Dario Gerace from the University of Pavia.

A new frontier in physics

The creation of a light-based supersolid represents a paradigm shift in how people think about matter and energy. It bridges the gap between fundamental science and practical applications, offering a new platform for exploring quantum phenomena.

As physicist Iacopo Carusotto from the University of Trento explains, “We can imagine the supersolid as a fluid composed of coherent quantum droplets periodically arranged in space. These droplets are able to flow through an obstacle without undergoing perturbations, maintaining their spatial arrangement and mutual distance unchanged as happens in a crystalline solid.”

This achievement not only validates decades of theoretical work but also paves the way for future discoveries. By harnessing the unique properties of supersolids, scientists may unlock technologies that were once the stuff of science fiction.

The study, published in Nature, is a testament to the power of interdisciplinary collaboration and the relentless pursuit of knowledge. As humans continue to push the boundaries of physics, the supersolid state of light stands as a shining example of what humanity can achieve when it dares to explore the unknown.

Sources include:

LiveScience.com

Nature.com

ScienceAlert.com