Magnetic-Electrical Synergetic Control of Non-Volatile States in Bilayer Graphene-CrOCl Heterostructures

Abstract

Anti-ferromagnetic insulator chromium oxychloride (CrOCl) has shown peculiar charge transfer and correlation-enhanced emerging properties when interfaced with other van der Waals conductive channels. However, the influence of its spin states to the channel material remains largely unknown. Here, this issue is addressed by directly measuring the density of states in bilayer graphene (BLG) interfaced with CrOCl via a high-precision capacitance measurement technique and a surprising hysteretic behavior in the charging states of the heterostructure is observed. Such hysteretic behavior depends only on the history of magnetization, but not on the history of electrical gating; it can also be turned off electrically, providing a synergetic control of these non-volatile states. First-principles calculations attribute this observation to magnetic field-controlled charge transfer between BLG and CrOCl during the phase transition of CrOCl from antiferromagnetic (AFM) to ferrimagnetic-like (FiM) states. This magnetic-electrical synergetic control mechanism broadens the scope of proximity effects and opens new possibilities for the design of advanced 2D heterostructures and devices.