Symmetry-dependent transport properties and bipolar spin filtering in zigzagα-graphyne nanoribbons

Abstract

First-principles calculations are performed to investigate the transport properties of zigzag α-graphyne nanoribbons (ZαGNRs). It is found that asymmetric ZαGNRs behave as conductors with linear current-voltage relationship, whereas symmetric ZαGNRs have very small currents under finite bias voltages, similar to those of zigzag graphene nanoribbons. The symmetry-dependent transport properties arise from different coupling rules between the π and π * subbands around the Fermi level, which are dependent on the wavefunction symmetry of the two subbands. Based on the coupling rules, we further demonstrate the bipolar spin-filtering effect in the symmetric ZαGNRs. It is shown that nearly 100% spin-polarized current can be produced and modulated by the direction of bias voltage and/or magnetization configuration of the electrodes. Moreover, the magnetoresistance effect with the order larger than 500,000% is also predicted. Our calculations suggest ZαGNRs as one of promising candidate materials for novel spintronics.

Symmetry-Dependent Spin Transport Properties and Spin-Filter Effects in Zigzag-Edged Germanene Nanoribbons

“…In contrast, the current for 5-ZGeNR with the AP configuration is almost independent of spin and shows a linear metallic behavior. This interesting phenomenon is very similar to those of [21,27,28], which is possible because of a symmetry selection rule that was first proposed by Li et al [27]. And, for symmetry one, the flexible control over spin current makes it possible to use the two-terminal device as a basic component for building multifunctional spintronic devices.…”

“…The spin configuration is crucial for the spin-filter effect, and many researchers have found that ZGNR, Z GNRs, and ZSiNR can show perfect spin-filter effect with AP configuration [12,21,27,28]. So, in here, as shown in Journal of Nanomaterials Spin-down state of 6-ZGeNR.…”

“…A feasible approach to realize germanene-based spintronics is to construct the device junctions of germanium nanoribbons (ZGeNRs) and then systematically study the transport properties as fundamental and crucial components of germanene-based circuits. Recently, intriguing transport phenomena have been found in zigzag graphene nanoribbons (ZGNRs) [27], zigzag -graphyne nanoribbons [28], and silicene nanoribbons (ZSiNRs) with buckled structure [21], where symmetric and asymmetric zigzag ribbons are found to have completely different -characteristics despite the similarity of their band structure. More interestingly, bipolar spin diode behavior was observed in symmetry devices.…”

Synthesis and Electronic Structure of Boron‐Graphdiyne with an sp‐Hybridized Carbon Skeleton and Its Application in Sodium Storage

“…Carbon allotropes are capable of forming different architectures with a variety of hybridized forms and molecular shapes, including the sp 3 ‐hybridized crystal‐like diamonds, sp 2 ‐hybridized porous covalent organic frameworks (COFs), sp 2 ‐hybridized spherically shaped fullerenes, sp 2 ‐hybridized latticed graphene, and sp 2 ‐hybridized aromatic nanobelts . Compare to the above well‐known carbon materials, novel carbon allotropes comprising quantitative content of sp‐hybridized carbon have drawn more and more attentions for their unusual predicted and experimental properties including unique electronic structures, excellent transport properties, and electro and chemical affinity . Profiting from the above unique characteristics, sp‐carbon rich materials have shown application prospects in many fields, especially in energy transfer and storage devices .…”

Designing cross-linked carbon nanotubes as perfect spin filter and spin valve

“…So far, many kinds of molecular materials have been chosen to construct the spintronic devices, such as carbon nanotubes (CNTs) [9][10][11][12], C 60 [13,14], graphene nanoribbons [15][16][17][18], zigzag a-graphyne nanoribbons [19], boron nitride nanoribbons [20], n-acenes family [21], etc. Especially, CNTs have greatly stimulated the interest of researchers due to their long phase-coherence and spin scattering lengths.…”