A wealth of remarkable behaviors is observed at the interfaces between magnetic oxides due to the coexistence of Coulomb repulsion and interatomic exchange interactions. While previous research has focused on bonded oxide heterointerfaces, studies on magnetism in van der Waals interfaces remain rare. In this study, we stacked two freestanding cobaltites with precisely controlled twist angles. Scanning transmission electron microscopy revealed clear and ordered moir\'e patterns, which exhibit an inverse relationship with the twist angle. We found that the Curie temperature in the twisted region is reduced by approximately 13 K compared to the single-layer region using nitrogen-vacancy (NV) magnetometry. This phenomenon may be related to the weakening of the orbital hybridization between oxygen ions and transition metal ions in the unbonded interfaces. Our findings suggest a potential avenue for modulating magnetic interactions in correlated systems through twist, providing opportunities for the discovery of unknown quantum states.
@article{arxiv.2412.03007,
title = {Deteriorated Interlayer Coupling in Twisted Bilayer Cobaltites},
author = {Dongke Rong and Xiuqi Chen and Shengru Chen and Jingfeng Zhang and Yue Xu and Yanxing Shang and Haitao Hong and Ting Cui and Qianying Wang and Chen Ge and Can Wang and Qiang Zheng and Qinghua Zhang and Lingfei Wang and Yu Deng and Kuijuan Jin and Gang-Qin Liu and Er-Jia Guo},
journal= {arXiv preprint arXiv:2412.03007},
year = {2025}
}