High performance current and spin diode of atomic carbon chain between transversely symmetric ribbon electrodes

TL;DR

This study demonstrates that atomic carbon chain devices with symmetric ferromagnetic graphene-nanoribbon electrodes can achieve giant current and spin rectification ratios, with potential applications in spintronic diodes.

Contribution

The paper introduces a novel atomic carbon chain diode with high spin rectification ratios enabled by symmetric electrode design and edge atom substitution, advancing spintronic device performance.

Findings

Pure spin current in parallel configuration.

Spin rectification ratio of order 10^4.

Current rectification ratio over 10^6 with boron substitution.

Abstract

We demonstrate that giant current and high spin rectification ratios can be achieved in atomic carbon chain devices connected between two symmetric ferromagnetic zigzag-graphene-nanoribbon electrodes. The spin dependent transport simulation is carried out by density functional theory combined with the non-equilibrium Green's function method. It is found that the transverse symmetries of the electronic wave functions in the nanoribbons and the carbon chain are critical to the spin transport modes. In the parallel magnetization configuration of two electrodes, pure spin current is observed in both linear and nonlinear regions. However, in the antiparallel configuration, the spin-up (down) current is prohibited under the positive (negative) voltage bias, which results in a spin rectification ratio of order 104. When edge carbon atoms are substituted with boron atoms to suppress the edge magnetization in one of the electrodes, we obtain a diode with current rectification ratio over 10e6.