Current-driven reversible ferromagnetic to antiferromagnetic transition in thin films and Devices

Electrical control of magnetic order is a central objective in condensed matter physics and spintronics, promising energy-efficient, high-density information technologies. In this endeavour, current state-of-the-art technologies like spin-transfer and spin–orbit torque-driven switching have gained potential interest, where the switching happens solely between two ferromagnetic states. However, electrically inducing a switching between ferromagnetic and antiferromagnetic phases, i.e., inverse metamagnetic transition, remains unrealized. Here, we show a reversible, current-driven inverse metamagnetic transition in epitaxial Sm_1-xSr_xMnO₃thin films. The system abruptly shifts from a low-resistance ferromagnetic state to a high-resistance antiferromagnetic-like phase above a critical current, concurrent with orbital polarization reorientation. This transition is confirmed by current-dependent X-ray magnetic circular dichorism (XMCD) and X-ray linear dichorism (XLD) measurements. Utilizing this phenomenon, we have fabricated nanoscale spin-filter tunnel junction devices based on LaNiO₃/Sm_1-xSr_xMnO₃/SrTiO₃/La_0.7Sr_0.3MnO₃ heterostructure, and we achieve bistable resistance switching with magnetoresistance exceeding 200%, tunable by current, temperature, and magnetic field. Our findings reveal a novel non-equilibrium mechanism for electrical magnetic phase control in complex oxides, opening new avenues beyond conventional torque-driven spintronics.