Giant multiphononic effects in a perovskite oxide

Perovskite oxides offer tremendous potential for applications in information storage and energy conversion, owing to a subtle interplay between their spin, charge, orbital and lattice degrees of freedom. Here, we further expand the possible range of perovskite oxides operation towards the fields of thermal management and thermal computing by exploiting an exceptional synergy between different ferroic orders. We propose dynamical control of the heat flow in a distinctive family of perovskite oxides obtained via the application of small electric (~10¿kV/cm) and/or magnetic (~1¿T) fields. Based on first-principles simulations, we predict a relative heat conductivity variation of ~100% in SrMnO3 thin films near room temperature resulting from a phase transition that involves huge changes in both the magnetization and electric polarization. The disclosed giant multiphononic effects are fundamentally caused by anharmonic spin-phonon couplings that strongly influence the mean lifetime of phonons.
We acknowledge financial support by MCIN/AEI/10.13039/501100011033 under grant PID2020-119777GB-I00, the Ramón y Cajal fellowship RYC2018-024947-I and the Severo Ochoa Centres of Excellence Program (CEX2019-000917-S), and by the Generalitat de Catalunya under grant no. and 2017 SGR 1506. Calculations were performed at the Centro de Supercomputación de Galicia (CESGA) within action FI2022-1-0012 of the Red Española de Supercomputación (RES). We also thank the support of the Luxembourg National Research Fund through project FNR/C18/MS/ 12705883/REFOX (J.Í.).
Peer Reviewed
Postprint (published version)