Real-space observation of ferroelastically-designed Jahn-Teller domains in a LaMnO3 film

The Jahn-Teller (JT) distortion, which removes electronic degeneracies through geometric deformation of molecules or local ionic lattices, lays the groundwork for many interesting phenomena observed in strongly correlated systems. Here, we report the real-space observation of JT domains and the orbiton-related domains in a LaMnO3 thin film using a confocal Raman spectromicroscopy [1]. Characteristic symmetries of JT-originated Raman modes allow us to detect and visualize the local population and orientation of JT planes. In conjunction with structure analysis, we find that the formation of ferroelastic domains with W or W' walls provides the basic framework for understanding JT domain textures. We also demonstrate the manipulation of the JT domains by the application of external stress. Our findings offer a new approach for the observation of orbital domains and provide a pathway for mechanically-tunable orbitronic applications.

[1] Y.-J. Kim, H.-S. Park, and C.-H. Yang, npj Quantum Mater., 6, 62 (2021).