Spin-selective transport through helical molecular systems

• Published in: Physical review. B, Condensed matter and materials physics Vol. 85; no. 8
• Main Authors: Gutierrez, R., Díaz, E., Naaman, R., Cuniberti, G.
• Format: Journal Article
• Language: English
• Published: 16-02-2012
• Subjects: Condensed matter; Coupling (molecular); Dispersions; Electronics; Helical; Low conductivity; Spin-orbit interactions; Transport
• ISSN: 1098-0121; 1550-235X
• DOI: 10.1103/PhysRevB.85.081404

Highly spin-selective transport of electrons through a helically shaped electrostatic potential is demonstrated in the frame of a minimal model approach. The effect is significant even for weak spin-orbit coupling. Two main factors determine the selectivity: an unconventional Rashba-like spin-orbit interaction, reflecting the helical symmetry of the system, and a weakly dispersive electronic band of the helical system. The weak electronic coupling, associated with the small dispersion, leads to a low mobility of the charges in the system and allows even weak spin-orbit interactions to be effective. The results are expected to be generic for chiral molecular systems displaying low spin-orbit coupling and low conductivity.