How sliding ferroelectric bilayers switch and why fatigue is weak
In plain words
Stacking two layers of boron nitride or of a semiconductor like MoS2 in a particular offset creates an electric dipole between them that flips when one layer slides by one atomic spacing. How the sliding proceeds through moving boundaries between domains, and what limits its speed and endurance, is unclear.
Precise statement
In parallel-stacked (AB/BA) bilayer hBN and transition-metal dichalcogenides, out-of-plane polarization reverses by interlayer translation of one bond length, mediated by motion of domain walls that are interlayer partial dislocations. Determine the switching pathway (wall nucleation versus depinning of pre-existing walls), the coercive field versus temperature and sample size, the intrinsic switching time, and why reported fatigue is weak. An answer is a domain-wall dynamics model matching measured coercive fields and switching times.
What would settle it
Time-resolved imaging of domain-wall motion during switching in a single device, compared with a model using computed stacking-fault energies and pinning by defects.
Status in the literature
Unverified note
Switching and high endurance were reported in hBN and TMD bilayers from 2021 to 2024; the role of domain-wall pinning has not been quantified.