Polarity‐Reversible Zero‐Field Diode Effect in van der Waals Ferromagnetic Josephson Junction for Logic Operation

With unprecedented energy efficiency and quantum-ready properties, superconducting electronics drive breakthroughs in quantum processors, ultra-precise sensors, and beyond-Moore's-law computing architectures. While nonreciprocal circuit elements such as superconducting diodes are essential for these systems, the realization of practical devices with robust performance remains a major challenge. In particular, polarity-tunable superconducting diodes that operate efficiently under zero magnetic field are highly desired for practical applications. Here, a polarity-reversible zero-field Josephson diode effect (JDE) is demonstrated with highly sustained performance in a vertically stacked 2D van der Waals (vdW) ferromagnetic Josephson junction composed of the Ising superconductor NbSe₂ and the itinerant ferromagnet Fe₃GeTe₂ (FGT) layers. The diode asymmetry and rectification polarity are primarily tunable via the magnetic state and thickness of the FGT layer. By optimizing the thickness of the FGT layer, a polarity-reversible JDE is achieved with a rectification efficiency of up to 34.1%. Furthermore, an exclusive OR (XOR) logic gate operation is successfully implemented using this reconfigurable JDE. The work establishes a new route toward realizing efficient, polarity-reversible, zero-field superconducting diodes and underscores their potential for 2D non-dissipative superconducting electronics.