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).