In a quiet laboratory in Innsbruck, a team of physicists has just opened a door that scientists have been knocking on for years. Led by Francesca Ferlaino, working alongside collaborators in Turin, researchers have proposed a new theoretical framework that predicts seven exotic phases of matter emerging from ultracold magnetic atoms—and including one state that has never been experimentally realized before.
The work, published in Nature Communications, centers on lanthanide atoms—specifically erbium and dysprosium—chilled to nearly absolute zero and trapped in a one-dimensional optical lattice. These atoms carry unusually large magnetic moments, which gave the team something precious: independent control over three key parameters that govern how quantum particles behave. They could tune how particles hop between lattice sites, how their spins interact, and how strongly they repel one another—all at once, something that hasn't been achievable with conventional atomic systems before.
"This exotic state of matter, in which topological order and and superconductivity are deeply intertwined, has not previously been experimentally realized," says lead author Leonardo Giacomelli, who works in Ferlaino's group at the University of Innsbruck. The state he and his colleagues are calling a topological triplet superconductor, it combines two remarkable phenomena into one: lossless electrical transport and topological order, a quantum condition that is unusually robust against environmental noise. That resilience is precisely what makes it so compelling for quantum computing, where errors are the persistent enemy.
Luca Barbiero from the Politecnico di Torino, who co-led the research, emphasizes that the team hasn't just predicted this phase—they've mapped out a detailed, step-by-step protocol for actually creating and detecting all seven predicted phases using existing quantum gas microscopy techniques. No far-future technology is required.
"Our study presents a concrete step toward a deeper understanding of the intriguing states of matter emerging in strongly interacting fermionic quantum matter," says Ferlaino. "The proposed platform is directly compatible with existing experimental setups, which is particularly relevant given that topological superconductors are among the most promising candidates for fault-tolerant quantum computing."
The work was conducted at the University of Innsbruck's Department of Experimental Physics and at the Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences. For Giacomelli and the team, the next step is watching these predictions become reality in hardware—and that moment may be closer than the field has dared to hope.