<< In work recently published (..), the mismatch of electronic momentum across domain walls (i.e., regions with a different orientation of the intrinsic electric dipole) is shown to create standing waves, even though there is no potential buildup across the domain wall. >>
Researchers demonstrate new properties of atomically thin ferroelectrics. University of Arkansas. May 28, 2019
https://m.phys.org/news/2019-05-properties-atomically-thin-ferroelectrics.html
Kai Chang, Brandon J. Miller, et al. Standing Waves Induced by Valley-Mismatched Domains in Ferroelectric SnTe Monolayers. Phys. Rev. Lett. 122, 206402 May 24, 2019.
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.122.206402