Researchers at Florida State University have uncovered a previously unknown quantum phase of matter in which electrons behave simultaneously like crystalline solids and free-flowing fluids.
The breakthrough, published in the journal NPJ Quantum Materials, could reshape our understanding of how matter behaves at a quantum level—and open fresh pathways for quantum computing, spintronics, and next-generation electronics.
At the center of the discovery is the generalized Wigner crystal, a long theorized lattice of electrons. But the FSU team found something even stranger. They identified a “pinball” phase in which some electrons lock into a crystal while others remain free to conduct electricity, even as the structure remains mostly solid.
By meticulously tuning the interactions of electrons in a two-dimensional moiré superlattice, the team demonstrated that solid-like and fluid-like electron behaviors can coexist—a hitherto unseen state of matter with profound implications for condensed-matter physics and quantum device engineering.
“This pinball phase is a very exciting phase of matter that we observed while researching the generalized Wigner crystal,” co-author and Assistant Professor of physics at FSU, Dr. Cyprian Lewandowski, said in a statement. “Some electrons want to freeze and others want to float around, which means that some are insulating and some are conducting electricity. This is the first time this unique quantum mechanical effect has been observed and reported for the electron density we studied in our work.”
The team’s work builds on the theoretical lineage of physicist Dr. Eugene Wigner, a Nobel laureate who proposed the “Wigner crystal” in 1934.
Dr. Wigner showed that when electrons become extremely dilute, their mutual repulsion can force them into a rigid, crystal-like pattern. In this state, electrons minimize their Coulomb energy by spacing themselves into an orderly lattice rather than moving freely.
But in most real materials, this perfect crystal never forms. Thermal motion, kinetic energy, and disorder usually melt the pattern before it can stabilize. To overcome these limits, researchers placed electrons inside a moiré superlattice—created by stacking two atomically thin TMD layers with a slight rotational twist. This structure slows the electrons down and enhances their interactions, making crystalline arrangements more likely.
The researchers then used several advanced numerical tools—exact diagonalization, density-matrix renormalization group (DMRG), and Monte Carlo simulations—to map the system’s full phase diagram. When they included the full long-range Coulomb interaction, the electrons formed stable generalized Wigner crystals at fractional fillings.
More surprising was the discovery of what the authors describe as a “pinball” phase. In this state, some of the electronic charge becomes localized on a fixed triangular pattern, while the remaining charge stays delocalized.
The partially ordered structure appears when certain interaction terms are included, leading to “charge centers… at sites of a triangular crystal… and the remaining… charge density… delocalized on the other sites.”
This hybrid state emerges from a balance between interaction energy and the kinetic energy of the mobile electrons.
“We study both classical and quantum effects at zero and finite temperatures, discussing the role of charge frustration, identifying a ‘pinball’ phase, a partially quantum melted GWC, with no classical analog,” the researchers write.
In the broader world of materials science, this discovery reshapes how researchers think about phase transitions in quantum systems. We’re used to matter shifting from solid to liquid to gas as heat is added. But in this regime, the “knobs” that drive change are quantum in nature. Factors like electron density, the moiré pattern of the material, and the distance to a nearby gate electrode all influence whether electrons behave like a rigid solid or a flowing liquid.
One of the most compelling outcomes of the work is the identification of a phase in which insulating and conducting behavior coexist. If engineers learn to control this hybrid state, they could create materials with isolated pockets of electrons that don’t move, sitting right next to channels where electrons flow freely. That level of control could form the basis for low-energy spintronics, more stable qubits, and highly sensitive quantum devices.
More broadly, the authors find that the generalized Wigner crystal itself sits close to a metal–insulator transition—a point at which a material can switch from carrying current to blocking it. They conclude that “the effective parameters situate the GWC close to the MIT,” a proximity that “may suggest it is fragile to added perturbations such as disorder.”
In practical terms, the electron lattice is stable but sensitive, so imperfections in a real material could help create small regions that behave more metallic or more insulating.
To understand how these phases might behave in realistic setups, the team examined their responses to different screening conditions. In their calculations, the distance between the sample and a nearby gate strongly affects how electrons interact with it. As the researchers note, they “predicted the impact of adjusting the gate-to-sample distance on charge and magnetic ordering temperature scales.”
When that distance becomes comparable to the spacing of the moiré lattice, the crystal-like order can begin to melt, and the authors note that achieving such conditions is within the reach of current experiments. That opens the door for lab measurements that directly track how these phases form and dissolve.
Materials that can host both mobile and immobilized electrons in the same atomic layer could unlock an entirely new class of quantum technologies. Devices that depend on precise control of electron motion—from qubits to advanced spintronic circuits to ultra-efficient logic components—stand to benefit from phases where solid-like and liquid-like behavior coexist.
As investment in quantum research accelerates, discoveries like this one help chart the course for future hardware. Understanding how electrons organize themselves under extreme quantum conditions offers a blueprint for designing materials that are smaller, more efficient, and far more capable than today’s classical electronics.
Nevertheless, the researchers emphasize that, while the theoretical predictions are robust, experimental verification and engineering are ongoing.
The next steps involve guiding experiments to observe the pinball phase in real moiré TMD systems, particularly by measuring melting temperatures, gate-distance dependencies, and spin correlations. The paper predicts magnetic crossover temperatures in the range of hundreds of millikelvin to a few kelvin—accessible with current cryogenic tools.
Ultimately, the discovery of this quantum “pinball” phase adds a striking new chapter to the physics of exotic matter. It shows that when electrons are placed in the right environment, they can break the usual rules—locking into crystalline patterns, moving like a fluid, and doing both at the same time.
This work sharpens a decades-old theory while pointing toward a future where materials can be engineered to host electrons that are part solid, part liquid, and entirely quantum in their behavior.
“What causes something to be insulating, conducting, or magnetic? Can we transmute something into a different state?” Dr. Lewandowski said. “We’re looking to predict where certain phases of matter exist and how one state can transition to another — when you think of turning a liquid into gas, you picture turning up a heat knob to get water to boil into steam.”
“Here, it turns out there are other quantum knobs we can play with to manipulate states of matter, which can lead to impressive advances in experimental research,” Lewandowski concludes.
Tim McMillan is a retired law enforcement executive, investigative reporter and co-founder of The Debrief. His writing typically focuses on defense, national security, the Intelligence Community and topics related to psychology. You can follow Tim on Twitter: @LtTimMcMillan. Tim can be reached by email: tim@thedebrief.org or through encrypted email: LtTimMcMillan@protonmail.com