Scientists have discovered a unique link between ferroelectric domain walls and superconductivity in two-dimensional van der Waals materials. The breakthrough is credited to research by Gaurav Chaudhary of the University of Cambridge and Ever Martin of Argonne National Laboratory, highlighting how specific structural properties in these materials enable strong electron interactions. These findings are expected to pave the way for new superconducting devices and advanced applications in the field of condensed matter physics.

Sliding ferroelectricity and polarization reversal

According to As phys.org reports, ferroelectric sliding in certain 2D van der Waals materials, including boron nitride and transition metal dichalcogenides (TMDs), facilitates polarization reversal under moderate electric fields. This phenomenon allows large-scale manipulation of the layer stacking, which significantly affects the electronic properties of the material. The researchers noted that domain walls—the boundaries separating regions with different directions of ferroelectric polarization—exhibit unique properties that enhance electron-phonon coupling.

Superconductivity was observed at the domain walls.

The study shows that in materials such as molybdenum ditelluride (MoTe₂), superconductivity is transiently enhanced near the ferroelectric reversal transition. This enhancement occurs within hysteresis loops where domains of different polarizations coexist. Dynamical fluctuations in the domain walls were identified as the driving mechanism for the pair interactions required for superconductivity. It is highlighted that these conditions are special for 2D TMDs, which support interlayer ferroelectricity while remaining conductive within their planes.

Future research and applications

Chowdhury and Martin indicated to phys.org that their findings have the potential to produce highly controllable superconducting devices. Efforts are underway to explore the systematic design of new superconductors by layering polar materials and exploiting domain wall networks in moiré systems. They also emphasized the need for further investigations to validate their theoretical models using advanced microscopic simulations.
The study has sparked interest among scientists aiming to uncover the unconventional mechanisms of superconductivity, a major step forward in understanding and exploiting the properties of 2D materials.