Title

Asymmetric ferroelectricity by design in atomic-layer superlattices with broken inversion symmetry

Document Type

Article

Publication Date

8-15-2021

Subject Area

ARRAY(0x55e0cb25a928)

Abstract

In atomic-layer superlattices constructed using three constituent phases, CaTiO3, SrTiO3, and BaTiO3, 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, our 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. We further show that both the magnitude and direction of this ferroelectric asymmetry can be controlled by the engineered atomic-layer stacking order and periodicity of the superlattice.

Publication Title

Physical Review B

Volume

104

Issue

8

Digital Object Identifier (DOI)

10.1103/PhysRevB.104.085103

ISSN

24699950

E-ISSN

24699969

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