Because of the remarkable semi-metallicity and edge states, graphene-based nanoelectronics has become an intense arena in low-dimensional atomic device science and technology. Nowadays, various single atomic chains have been successfully fabricated, which can serve as multi-functional interconnects to bridge atomic devices. Using first principles approach, the spintronic applications of graphene-based carbon atomic chains and boron nitride atomic chains MTJs (magnetic tunnelling junctions) are systematically investigated in this work. The results show that the half-metallicity is only contact-dominated (sp and sp² contacts), which cannot be switched by gate voltages, strain, the length of atomic chains, or the width of zigzag graphene nanoribbon leads. The intrinsic physics is that the electronic coupling in sp junctions provides partial transmission states for both spin currents, while one spin state is completely blocked by the electronic coupling in sp² junctions. Therefore, the sp² junctions present half-metallicity and remarkable tunnelling magneto-resistance (10⁵%–10⁶%), demonstrating the potential applications as spin-valve.

由于显着的半金属性和边缘态，基于石墨烯的纳米电子学已成为低维原子器件科学和技术中的一个激烈领域。如今，已经成功地制造了各种单原子链，它们可以用作桥接原子装置的多功能互连。使用第一原理方法，在这项工作中系统地研究了石墨烯基碳原子链和氮化硼原子链MTJ（磁性隧穿结）的自旋电子应用。结果表明，半金属仅是接触支配的（sp和sp ²触点），无法通过栅极电压，应变，原子链的长度或之字形石墨烯纳米带引线的宽度进行切换。本质上的物理学是，sp结中的电子耦合为两个自旋电流提供了部分传输状态，而一个自旋状态被sp ²结中的电子耦合完全阻止了。因此，sp ²结呈现出半金属性和显着的隧穿磁阻（10 ⁵％–10 ⁶％），证明了其作为自旋阀的潜在应用。