Researchers have achieved a breakthrough in quantum physics, observing a superfluid state of matter transition into a supersolid – and then revert back – for the first time. This reversible phase shift, detailed in a January 28th Nature study, confirms a previously theoretical possibility and opens new avenues for understanding exotic states of matter.
The Strange World of Quantum Phases
Most people are familiar with three common phases: solid, liquid, and gas. However, under extreme conditions, matter can exist in many other states. Superfluids are one such example: they flow without any resistance, even forming perpetual quantum vortices when stirred, and appear only at temperatures just above absolute zero.
Supersolids, theorized to arise from even colder superfluids, combine zero viscosity with crystalline order. Unlike typical liquids, particles in a supersolid arrange themselves into a lattice while retaining their ability to flow and form quantum vortices.
The Experiment & Key Findings
Previous attempts to create supersolids relied on external manipulation to force particles into a lattice structure. This new research demonstrates a natural phase transition: the superfluid spontaneously organizing into a supersolid under the right conditions.
To achieve this, the team sandwiched two graphene sheets together and exposed them to a strong magnetic field, creating an “exciton soup.” Excitons, quasiparticles formed from electron-hole pairs, behaved unexpectedly as the system cooled.
From Superfluid to Supersolid
At temperatures between 2.7 and 7.2°F (1.5–4°C) above absolute zero, the excitons formed a superfluid. Further cooling induced a shift to an electrically insulating phase, which the researchers believe is a genuine supersolid state.
As Jia Li, a physicist at the University of Texas at Austin, explained: “Observing an insulating phase that melts into a superfluid is unprecedented. This strongly suggests that the low-temperature phase is a highly unusual exciton solid.”
Why This Matters
This discovery matters because it validates fundamental theoretical predictions about matter’s behavior at extreme temperatures. The ability to naturally induce this phase transition suggests a deeper, inherent stability in these exotic states.
The implications go beyond pure physics. Understanding supersolids could unlock new technologies: materials with zero resistance could revolutionize energy transmission, while the unique properties of these phases might lead to novel quantum devices.
What’s Next?
The team plans to explore other materials and refine measurement techniques to further characterize the exciton supersolid state. Cory Dean, a physicist at Columbia University, stated that “For now, we’re exploring the boundaries around this insulating state, while building new tools to measure it directly.”
This research is not just about witnessing a strange phenomenon; it’s about pushing the boundaries of our understanding of matter and paving the way for future technological breakthroughs.
Ultimately, this discovery confirms that the universe holds even stranger surprises than we previously imagined, and that the quest to understand its fundamental laws is far from over.
