Unlocking Light: Scientists Create Supersolid State with Quantum Theatre Breakthrough

Light usually zips along at 300,000 kilometers per second in a vacuum, and you can’t trap it because it’s made of massless particles called photons. These photons typically act like either waves or particles. However, researchers at Italy’s University of Pavia and CNR Nanotec have recently changed the game by successfully "freezing" light in a controlled ultra-cold environment, turning it into a unique state of matter called a supersolid. Their findings were published in Nature.

What Is a Supersolid?

A supersolid blends characteristics of solids and superfluids. While solids are generally rigid, a supersolid can flow like a fluid without viscosity, all while maintaining a crystalline structure. It’s like a highly organized dance of particles that can adjust based on how they interact with each other.

The concept of a supersolid isn’t entirely new. The idea was first proposed around the 1960s, and in 2017, it was created in a lab for the first time. Earlier, researchers had found ways to slow light down significantly—like in 1999, when Danish physicist Lene Hau slowed a beam of light to just 17 meters per second using a Bose-Einstein condensate. They later managed to stop a light pulse completely by storing its information in atoms, essentially "freezing" it temporarily.

In 2010, teams in Germany created a state of "liquid light" using photons in a confined environment. Yet, this was still not a solid form of light.

The Role of Polaritons

The recent study achieved a significant milestone by coupling light with matter to create a true supersolid. This opens exciting new pathways in condensed matter physics, a field crucial for technologies like optical fibers and quantum computing.

Polaritons are at the heart of this new research. These hybrid particles act like both light and matter and form when photons connect with energy packets such as phonons or excitons. The researchers used a special semiconductor platform and a pulsed laser to maintain a dense condensate of polaritons at nearly absolute zero temperature.

When the laser light entered the semiconductor, polaritons formed and were trapped in a periodic pattern. They organized themselves into a structure reminiscent of crystalline solids. The result was light behaving like a supersolid, similar to how atoms are arranged in diamonds or quartz.

A Fun Analogy

In describing their findings, the researchers likened the polariton behaviors to a "quantum theatre." Imagine a crowded theater with only a few seats left. Everyone wants the best one, but it can fit just one person. In this quantum scenario, however, multiple particles can share that best seat, leading to the formation of a dense condensate.

Future Possibilities

The study showcases that under the right conditions, light can express states of matter not traditionally associated with it. This could have exciting implications, like enabling more efficient optical energy transport and enhancing optical computing technologies.

In summary, the ability to manipulate light in such a groundbreaking way could lead to new advancements in various fields, offering both theoretical insights and practical applications.

For more details, read the study published in Nature here.

Shamim Haque Mondal is a researcher in the Physics Division at the State Forensic Science Laboratory in Kolkata.

Source link