Scientists found electrons frozen into a solid crystal that still flow like a liquid, which is a 'solid liquid' that shouldn't exist.
April 2, 2026
Original Paper
Evidence of Metallic Wigner Crystal in Rhombohedral Graphene
arXiv · 2604.00113
The Takeaway
Normally, when electrons 'freeze' into a Wigner crystal, they get stuck in place and the material becomes an insulator. Researchers found a version where the electrons are locked into a grid but still conduct electricity, essentially existing as a solid and a liquid at the same time.
From the abstract
When the Coulomb interaction dominates over kinetic energy, electrons can crystallize into a Wigner crystal (WC). This paradigmatic correlated electronic phase has been realized in two-dimensional electron gases with parabolic band dispersion and completely flat Landau levels under high magnetic fields. Beyond these conventional contexts of electron crystallization, more exotic electron crystals have been postulated but remain unexplored. For example, a metallic Wigner crystal (mWC), in which it