This study presents a novel approach to create all-antiferromagnetic tunnel junctions (MTJs) at the atomic limit using a twisting strategy. The researchers demonstrate that by twisting two bilayers of CrSBr, a 2D antiferromagnet, they achieve a more than 700% nonvolatile tunnelling magnetoresistance (TMR) ratio at zero field. The entire twisted stack functions as the tunnel barrier, and the TMR is derived from coherent tunneling across the individual CrSBr monolayers. The TMR dependence on the twist angle is calculated from the electron-parallel momentum-dependent decay across the twisted monolayers, showing excellent agreement with experimental results. The twisted junctions exhibit a much weaker temperature dependence of TMR compared to untwisted junctions, making them more attractive for applications. The work shows that nonvolatile magnetic information storage can be pushed to the atomically thin limit. The study also explores the physical mechanisms behind the giant TMR effect, revealing that the spin-dependent potential barrier of CrSBr is twist-angle-dependent. The results highlight the potential of 2D antiferromagnetic materials for next-generation spintronic devices with ultrafast and high-density capabilities. The research provides a compelling strategy for achieving all-antiferromagnetic MTJs in the atomic limit, demonstrating the feasibility of nonvolatile magnetic storage at the atomic scale.This study presents a novel approach to create all-antiferromagnetic tunnel junctions (MTJs) at the atomic limit using a twisting strategy. The researchers demonstrate that by twisting two bilayers of CrSBr, a 2D antiferromagnet, they achieve a more than 700% nonvolatile tunnelling magnetoresistance (TMR) ratio at zero field. The entire twisted stack functions as the tunnel barrier, and the TMR is derived from coherent tunneling across the individual CrSBr monolayers. The TMR dependence on the twist angle is calculated from the electron-parallel momentum-dependent decay across the twisted monolayers, showing excellent agreement with experimental results. The twisted junctions exhibit a much weaker temperature dependence of TMR compared to untwisted junctions, making them more attractive for applications. The work shows that nonvolatile magnetic information storage can be pushed to the atomically thin limit. The study also explores the physical mechanisms behind the giant TMR effect, revealing that the spin-dependent potential barrier of CrSBr is twist-angle-dependent. The results highlight the potential of 2D antiferromagnetic materials for next-generation spintronic devices with ultrafast and high-density capabilities. The research provides a compelling strategy for achieving all-antiferromagnetic MTJs in the atomic limit, demonstrating the feasibility of nonvolatile magnetic storage at the atomic scale.