AA << demonstrated this phenomenon for the first time in engineered two-dimensional crystals. (..) These engineered crystals lead to an asymmetric bi-stability with two unequal stable polarization states in contrast to a natural ferroelectric. >>
New electronic phenomenon discovered. University of North Florida. Aug 11, 2021.
<< In atomic-layer superlattices constructed using three constituent phases, (..) the stacking sequence of the atomic layers is found to control the symmetry of the high-temperature dielectric response. In such a superlattice when a nanostructured asymmetric strain is programmed into the lattice via the stacking order, the natural symmetry at high temperatures is removed and a polarized sample is obtained in which the polarization increases as the temperature is lowered. In contrast to a ferroelectric characterized by a bistable ground state with two equal and opposite electronic polarizations, (they) experiments show evidence of asymmetric ferroelectric correlations that set in when such a sample becomes hysteretic below a temperature Tx, with two unequal polarization states. >>
Maitri P. Warusawithana, Caitlin S. Kengle, et al. Asymmetric ferroelectricity by design in atomic-layer superlattices with broken inversion symmetry. Phys. Rev. B 104, 085103. Aug 4, 2021.
