Perfect Spin Filter in a Tailored Zigzag Graphene Nanoribbon

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Zigzag graphene nanoribbons (ZGNRs) are key components for all-carbon spintronic devices.
• Fabricating ZGNR-based devices with high spin-filter efficiency and low experimental complexity remains a challenge.

Purpose of the Study:

• To investigate the spin-dependent transport properties of tailored zigzag graphene nanoribbons.
• To explore the potential for achieving perfect spin-filtering effects in ZGNR structures.

Main Methods:

• Utilizing density functional theory (DFT) calculations.
• Employing the nonequilibrium Green's function (NEGF) technique to study transport properties.

Main Results:

• A perfect spin-filtering effect was observed in the tailored ZGNR structure.
• Nearly 100% spin-polarized current and a high magnetoresistance ratio were achieved with an applied magnetic field.
• The distribution of spin-up and spin-down states at bridge carbon atoms was identified as crucial for perfect spin filtering.

Conclusions:

• Tailoring ZGNRs presents an effective strategy for advancing graphene-based spintronics.
• The findings pave the way for developing high-performance spintronic devices with enhanced spin-filtering capabilities.