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Dipole-Induced Inversion of Spin-Dependent Charge Transport through α-Helical Peptide-Based Single-Molecule
Albert C Aragonès1, Monica Varese2, Kavita Garg3
1Departament de Ciència de Materials i Química Física, Institut de Química Teòrica i Computacional, University of Barcelona (UB), Marti i Franquès 1, 08028 Barcelona, Spain.
Journal of the American Chemical Society
|September 30, 2025
Summary
Researchers observed a novel phenomenon where electric dipole inversion in a chiral peptide junction alters electron spin-dependent conductance. This finding links the Chirality-Induced Spin Selectivity effect with spinterface properties for controlling spin transport.
Area of Science:
- Molecular electronics
- Spintronics
- Biophysics
Background:
- Chirality-Induced Spin Selectivity (CISS) effect governs spin polarization in chiral molecules.
- Single-molecule junctions offer a platform to study fundamental electron transport phenomena.
Purpose of the Study:
- Investigate the impact of electric dipole inversion on spin-dependent conductance in a chiral peptide junction.
- Explore the interplay between electric dipoles, atomic spin densities, and the CISS effect.
Main Methods:
- Fabrication and characterization of a 2-terminal single-molecule junction using a chiral α-helical peptide.
- Experimental measurements of electron transport properties.
- Computational modeling using a spinterface model.
Main Results:
- Observed enantiomeric inversion of electron spin-dependent conductance.
- Demonstrated that electric dipole inversion, not chiral symmetry change, controls conductance inversion.
- Rationalized results via a spinterface model incorporating electric dipole and spin moment effects.
Conclusions:
- Electric dipole inversion in chiral peptide junctions can invert spin-dependent transport.
- The phenomenon arises from the combined influence of the CISS effect and electrode/molecule spinterface properties.
- This provides a new mechanism for controlling spin transport at the molecular level.
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