Magnetoresistance effect based on spin-selective transport in nanodevices using chiral molecules

Area of Science:

• Spintronics
• Molecular electronics
• Materials science

Background:

• Chirality-induced spin selectivity (CISS) is a phenomenon observed in chiral molecules.
• CISS is of interest for magnetoresistance (MR) device applications.
• Fabricating nanodevices with chiral molecules presents unique challenges.

Purpose of the Study:

• To fabricate and characterize CISS-based nanodevices using chiral molecules.
• To investigate the magnetoresistance (MR) effect in these nanodevices.
• To explore the potential for low-magnetic-field MR devices.

Main Methods:

• Synthesis of the chiral molecule N-(3S)-3,7-dimethyloctyl[1]benzothieno[3,2-b]benzothiophene-2-carboxyamide (S-BTBT-CONHR).
• Fabrication of nanodevices with S-BTBT-CONHR sandwiched between Ni₇₈Fe₂₂ and Au electrodes.
• Characterization using magnetic conductive atomic force microscopy (mc-AFM) to observe spin selectivity and MR effect.

Main Results:

• High spin selectivity was observed in S-BTBT-CONHR thin films.
• Successful fabrication of Au/S-BTBT-CONHR/Ni₇₈Fe₂₂ nanodevices.
• Observation of the MR effect under low magnetic fields at room temperature, correlating with Ni₇₈Fe₂₂ magnetization.

Conclusions:

• CISS-based MR effect is successfully demonstrated in nanodevices under low magnetic fields.
• The study highlights the potential for developing novel MR devices utilizing chiral molecules.
• Provides insights into the CISS effect mechanism in device architectures.