Axisymmetric All-Carbon Devices with High-Spin Filter Efficiency, Large-Spin Rectifying, and Strong-Spin Negative Differential Resistance Properties

We propose the perfect all-carbon axisymmetric spintronic devices consisting of a zigzag-edged trigonal graphene (ZTG) linked to left and right zigzag-edged graphene nanoribbons (ZGNR) electrodes via carbon atomic chains (CACs). To ensure the stability of the system, the edge carbon atoms are passivated by hydrogen atoms. The self-consistent density functional theory (DFT) calculations show that the simple all-carbon system possesses the prefect spin-filtering property at a wide voltage region from -1.0 to 1.0 V. More importantly, the proposed system can act as a perfect dual spin diode in the antiparallel (AP) spin configuration, and the single-spin rectifying ratio can reach 103. When we add the number of the CACs linked to the left ZGNR electrode, the device shows the obvious single-spin negative differential resistance (NDR) behavior, which originates from the appearance of the localized states in the region of the left ZGNR electrode and ZTG. Meanwhile, the perfect spin-filtering and dual spin-diode properties are also retained in the all-carbon spintronic device, and the single-spin rectifying ratio can be enhanced to about 10(4).