Enhancement of Chirality-Induced Spin Selectivity by Strong Electron Correlations

TL;DR

This paper investigates how strong electron correlations enhance the spin selectivity in chiral molecules, explaining experimentally observed high spin polarization through theoretical modeling.

Contribution

It introduces a theoretical framework combining renormalized mean-field theory and Landauer-Büttiker formulas to analyze electron correlation effects on spin polarization in chiral molecules.

Findings

Significant spin polarization of 46.5% near Coulomb repulsion limit

Electron correlation increases average spin polarization by 2 to 4 times

Study reveals parameter dependence and Metal-Insulator transition effects

Abstract

Chirality-induced spin selectivity is a spin-splitting phenomenon from a helical structure with a considerably effective spin-orbit coupling. This unexpectedly large spin-splitting phenomenon has been experimentally observed in chiral organic molecules, which typically show a weak spin-orbit coupling. To understand this, we use the renormalized mean-field theory and Landauer-B\"{u}ttiker formulas to study the transport properties of single-stranded DNA in the presence of strong electron correlation. It shows a significant spin polarization of 46.5% near the Coulomb repulsion limit, which explains the extremely high spin polarization observed in experiments. Compared to systems without electron correlation, the averaged spin polarization in this case is 2 to 4 times greater across various system sizes. Furthermore, the parameter dependence of the spin polarization and the underlying Metal-Insulator transition are studied.