Light‐Induced Mott‐Insulator‐to‐Metal Phase Transition in Ultrathin Intermediate‐Spin Ferromagnetic Perovskite Ruthenates
Ruxin Liu, Liang Si, Wei Niu, Xu Zhang, Zhong‐Qiang Chen, Changzheng Zhu, Wenzhuo Zhuang, Yongda Chen, Liqi Zhou, Chunchen Zhang, Peng Wang, Fengqi Song, Lin Tang, Yongbing Xu, Zhicheng Zhong, Rong Zhang, Xuefeng Wang
Abstract
Abstract Light control of emergent quantum phenomena is a widely used external stimulus for quantum materials. Generally, perovskite strontium ruthenate SrRuO 3 has an itinerant ferromagnetism with a low‐spin state. However, the phase of intermediate‐spin (IS) ferromagnetic metallic state has never been seen. Here, by means of UV‐light irradiation, a photocarrier‐doping‐induced Mott‐insulator‐to‐metal phase transition is shown in a few atomic layers of perovskite IS ferromagnetic SrRuO 3− δ . This new metastable IS metallic phase can be reversibly regulated due to the convenient photocharge transfer from SrTiO 3 substrates to SrRuO 3− δ ultrathin films. These dynamical mean‐field theory calculations further verify such photoinduced electronic phase transformation, owing to oxygen vacancies and orbital reconstruction. The optical manipulation of charge‐transfer finesse is an alternative pathway toward discovering novel metastable phases in strongly correlated systems and facilitates potential light‐controlled device applications in optoelectronics and spintronics.