Physical Review Letters 135, 046201 (2025)

Superlubric Motion of Wavelike Domain Walls in Sliding Ferroelectrics

Changming Ke1,2, Fucai Liu3,4, and Shi Liu1,2,*
1. Westlake University  |  2. Westlake Institute for Advanced Study
3. UESTC (Chengdu)  |  4. State Key Laboratory of Electronic Thin FilmsBeijing

The Challenge

Sliding ferroelectrics offer exceptional properties, but the widely accepted switching mechanism—synchronized long-distance translation of entire atomic layers—contradicts experimental findings and violates Neumann’s principle.

Methodology

We reveal that polarization reversal relies on symmetry-breaking domain walls (DWs). Unlike the narrow DW mechanism recognized for decades, we demonstrate that wide, wavelike DWs coherently propagate through the material.

Key Insights

  • Quantum Nature Highlighted: The process relies on the tensorial nature of Born effective charges.
  • Superlubric Dynamics: These wavelike DWs exhibit almost frictionless motion.
  • Anomalous Behavior: Switching speed actually increases as the material cools down (cooling-promoted).
~4000 m/s Ultrahigh Velocity at Room Temp