Topological phonons in oxide perovskites controlled by light*

Oxide perovskites have received widespread attention ever since their discovery due to the multiple physical properties they exhibit, including ferroelectricity and superconductivity. We find that topological phonons – nodal rings, nodal lines, and Weyl points – are ubiquitous in oxide perovskites in terms of structures (tetragonal, orthorhombic, and rhombohedral), compounds (BaTiO₃, PbTiO₃, and SrTiO₃), and external conditions (photoexcitation, strain, and temperature). In addition, photoexcitation can be used to control the emergent topological states, for example driving the creation/annihilation of Weyl points and switching between nodal lines and nodal rings. Overall, we propose oxide perovskites as a versatile platform in which to study topological phonons and their manipulation with light [1]. Our discovery opens the door for studying topology-related phenomena in this family of materials, which may facilitate integration of topology-driven phenomena in technological devices based on oxide perovskites.

Reference:
[1] Bo Peng, Yuchen Hu, Shuichi Murakami, Tiantian Zhang, Bartomeu Monserrat. Topological phonons in oxide perovskites controlled by light. Science Advances 6, eabd1618 (2020).