Seven exotic quantum phases predicted in ultracold magnetic atoms, including topological superconductivity

14/07/2026
The researchers developed a realistic experimental setup based on ultracold magnetic lanthanide atoms trapped in a one-dimensional optical lattice. Credit: University of Innsbruck


Strongly interacting quantum particles are key to some of the most fascinating phenomena in modern physics—from magnetism and superconductivity to topological states. Yet the complexity of such systems makes many of their properties difficult to understand even today. A research team from Innsbruck and Turin has now proposed a new theoretical framework for generating and studying these exotic states of matter in ultracold magnetic atoms in a one-dimensional lattice.

Researchers led by Francesca Ferlaino and Luca Barbiero have developed the model that reveals seven exotic phases of matter. Most remarkably, one phase combines topological order and superconductivity, with potential applications in quantum computing. The team has provided a detailed roadmap for realizing and detecting these using existing experimental techniques in an article published in Nature Communications.

A new quantum model for magnetic atoms

At the heart of the study is a specially designed theoretical model, a well-established framework in quantum physics used to describe the behavior of strongly interacting quantum particles called fermions. The researchers developed a realistic experimental setup based on ultracold magnetic lanthanide atoms, specifically erbium and dysprosium, trapped in a one-dimensional optical lattice.

Thanks to the exceptionally large magnetic moments of these atoms, the team was able to construct a system in which three key parameters—how particles move between lattice sites, how their spins interact with one another, and how strongly they repel each other when occupying the same site—can be tuned independently. This level of control goes significantly beyond what has been achievable with conventional atomic systems.


Illustration of the model. Credit: Nature Communications (2026). DOI: 10.1038/s41467-026-71248-8


A topological superconductor

Using a combination of analytical methods and advanced numerical simulations, the team mapped out a rich phase diagram comprising seven distinct quantum phases. These include several forms of one-dimensional superconductivity, a topological liquid and, notably, a topological triplet superconductor. In this state, superconductivity—that is, the lossless transport of electric charge—coexists with topological order, a quantum state that is robust against environmental noise.

"This exotic state of matter, in which topological order and superconductivity are deeply intertwined, has not previously been experimentally realized," explains lead author Leonardo Giacomelli from the team of Ferlaino. "Our approach provides a concrete and experimentally accessible platform for this," adds Barbiero of the Politecnico di Torino.

A path to experimental realization

The researchers have developed a detailed, step-by-step protocol for preparing and detecting all the predicted quantum phases using quantum gas microscopy techniques.

"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 Department of Experimental Physics at the University of Innsbruck and the Institute for Quantum Optics and Quantum Information (IQOQI) of the Austrian Academy of Sciences (ÖAW).

Source https://tinyurl.com/mpp34rck via Phys.org