Spin dynamics in helical molecules with non-linear interactions

TL;DR

This paper introduces a model for spin dynamics in deformable helical molecules, revealing that electron-lattice interactions can produce stable spin-polarized solitons, advancing understanding of spin transport in molecular systems.

Contribution

It presents a novel effective model incorporating molecular deformation and weak spin-orbit coupling, highlighting the formation of stable spin-polarized solitons in helical molecules.

Findings

Electron-lattice interaction enables stable bright solitons with defined spin projection.

The model predicts soliton formation impacts spin transport in deformable molecules.

Study enhances understanding of spin dynamics considering molecular deformation.

Abstract

It is widely admitted that the helical conformation of certain chiral molecules may induce a sizable spin selectivity observed in experiments. Spin selectivity arises as a result of the interplay between a helicity-induced spin-orbit coupling and electric dipole fields in the molecule. From the theoretical point of view, different phenomena might affect the spin dynamics in helical molecules, such as quantum dephasing, dissipation and the role of metallic contacts. Previous studies neglected the local deformation of the molecule about the carrier thus far, but this assumption seems unrealistic to describe charge transport in molecular systems. We introduce an effective model describing the electron spin dynamics in a deformable helical molecule with weak spin-orbit coupling. We find that the electron-lattice interaction allows the formation of stable solitons such as bright solitons with well defined spin projection onto the molecule axis. We present a thorough study of these bright solitons and analyze their possible impact on the spin dynamics in deformable helical molecules.