Twisted molecular wires polarize spin currents at room temperature

Area of Science:

• Spintronics
• Molecular electronics
• Chiral materials science

Background:

• Developing molecular wires for efficient spin-polarized currents is a key challenge in spintronics.
• Chirality-induced spin selectivity (CISS) is a phenomenon that can generate spin polarization in chiral materials.

Purpose of the Study:

• To design and demonstrate molecular wires capable of rendering efficiently spin-polarized currents.
• To leverage interplanar torsional twisting and chiral ligands to enhance spin polarization.

Main Methods:

• Synthesis of highly conjugated molecular wires with chiral binucleating ligands.
• Characterization of optical properties, including near-infrared rotational strengths and electric/magnetic dipole transition moments.
• Experimental validation using magnetic-conductive atomic force microscopy and spin-Hall devices.

Main Results:

• Interplanar torsional twisting in chiral molecular wires leads to large near-infrared rotational strengths.
• A large scalar product of electric and magnetic dipole transition moments was observed.
• Demonstrated high spin selectivity and large-magnitude spin currents in these chiral materials.

Conclusions:

• Molecular wire designs incorporating chiral ligands and torsional twisting can achieve efficient spin polarization.
• These findings offer a promising route towards high-performance spintronic devices based on chiral materials.