Proximity-Induced Spin Filtering in vdW CrSBr Spin Valves with ZrTe5 Barriers

Two-dimensional (2D) materials have attracted significant interest for their exceptional physical properties and potential applications in nanoelectronics, spintronics, and optoelectronics. The emergence of van der Waals (vdW) heterostructures has further expanded this field by enabling the integration of complementary 2D layers, resulting in novel functionalities such as tunable band alignment, improved spin transfer, and proximity-induced effects like magnetism and superconductivity, making them ideal for advanced electronic devices. The combination of ferromagnetic semiconductors and semimetals offers new possibilities for exploring spin-polarized currents and improving spin injection efficiency. In this study, we investigate the 2D interface of the semimetal ZrTe5 and the ferromagnetic semiconductor CrSBr, focusing on their structural, electronic, and magnetic properties using first-principles calculations. Our results show that spin-up carriers dominate, with a spin polarization of approximately 75.08% at the Fermi level. The coupling of CrSBr with a monolayer of ZrTe5 significantly enhances the magnetic moment of the system due to proximity effects. We further investigate the CrSBr/nL - ZrTe5/CrSBr spin-valve heterostructure by systematically reducing the ZrTe5 layer thickness from five layers to a monolayer under parallel (P) and antiparallel (AP) spin alignments. The P configuration exhibits an increased magnetic moment in ZrTe5 with decreasing thickness, while the AP configuration results in the cancellation of the total magnetic moment. Transport calculations reveal a magnetoresistance (MR) ratio of 495.75% at zero bias for the single-layer ZrTe5 structure. The ZrTe5 interface enhances spin injection efficiency to over 90% in both P and AP configurations under bias voltage, enabling precise control of spin-polarized currents and highly effective spin filtering. This performance remains robust across a wide voltage range, despite the reduction of ZrTe5 layers from five to one, demonstrating the heterostructure’s structural stability and adaptability. These findings establish the CrSBr/ZrTe5/CrSBr system as a reliable and scalable platform for high-efficiency spin filtering and magnetic memory devices, positioning it as a promising candidate for next-generation spintronic technologies.