Discovery of the microscopic origin of electronic nematicity in a kagome material
10.02.2026
A research team from the Universities of Padua and Bologna has published in ««Nature Communications» the results of a study that, for the first time, demonstrates how electronic nematicity in a kagome material arises from a purely electronic mechanism. This discovery is a decisive step in understanding the fundamental principles of quantum materials, providing a solid basis for interpreting phenomena such as superconductivity.
"Electronic nematicity has long been considered an essential ingredient for describing the properties of quantum materials, but there was a lack of clear experimental evidence of its fundamental origin," explain Federico Mazzola from the Department of Physics and Astronomy "Galileo Galilei" at the University of Padua, and Domenico Di Sante from the Department of Physics and Astronomy "Augusto Righi" at the University of Bologna. "In this work, we show that the mechanism is intrinsic and electronic, providing the first experimental evidence of a Pomeranchuk instability in a real kagome material."
Kagome materials constitute an emerging class of quantum materials where the particular geometry of the electronic lattice favours collective behaviours of the electrons. In these systems, electrons do not move independently but tend to organise themselves, giving rise to unexpected properties. Among these phenomena is electronic nematicity, a form of self-organisation in which electrons spontaneously break the rotational symmetry of the system, choosing a preferred direction.
By studying the compound CsTi3Bi5, the researchers demonstrated that electronic nematicity arises from a purely electronic mechanism. The group combined advanced photoelectron spectroscopy experiments and theoretical calculations to show that nematicity in CsTi3Bi5 is the result of an intrinsic electronic instability, identifying a Pomeranchuk instability. This reorganisation deforms the material's electronic structure and reduces its symmetry without altering the arrangement of atoms.
The discovery suggests that similar electronic instabilities may be common in materials with complex band structures, opening new perspectives for the design of quantum materials with controllable properties.
