Van der Waals Magnetic Heterojunctions with Giant Zero‐Bias Tunneling Magnetoresistance and Photo‐Assisted Magnetic Memory

Abstract Van der Waals (vdW) magnetic heterostructures can offer much improved performance in logical operation and information storage technology compared with conventional ones. However, it is still challenging to achieve the perfect spin‐filtering capability in the vdW magnetic devices, a major obstacle to the advancement of low‐dimensional magnetic information storage. Herein, this study reports two newly designed vdW magnetic multilayers, ZrTe 2 /CrOCl/CrOX/ZrTe 2 (X = Cl, Br), where the CrOCl/CrOX bilayer acts as the spin‐filter tunnel barriers. With the vdW interfacial engineering and the doubly spin‐filtering effect of the CrOCl/CrOX bilayer, the vdW four‐layer heterostructures can potentially function as a perfect zero‐bias spin filter with giant spin‐filter energy‐dependent tunnel magnetoresistance up to 48 000%. Importantly, these calculations also show that the CrOCl/CrOBr bilayer without the 1T‐ZrTe 2 stacking can produce intensive and weak photo‐carrier transmission at parallel and antiparallel magnetization states, respectively. As such, the two contrasting photoelectric responses can be implemented for encoding the digital information as “‘1”’ and “‘0”’ via flipping the interlayer magnetic states. These novel functionalities not only endow the CrOCl/CrOX bilayer as a promising candidate for spin‐based vdW devices but also facilitate the future development of atomically thin magnetic information storage.