An argument why the Spinterface model cannot explain the chirality induced spin selectivity effect

TL;DR

This paper critically examines the Spinterface model for chirality induced spin selectivity, arguing that strong spin-orbit coupling alone cannot stabilize interfacial spin moments, challenging existing explanations.

Contribution

It provides a theoretical analysis showing that spin-orbit coupling and electron flux are insufficient for spin moment formation at chiral molecule-metal interfaces.

Findings

Strong spin-orbit coupling does not stabilize spin moments at the interface.

Electron flux does not induce spin moments, regardless of spin polarization.

The Spinterface model cannot fully explain the CISS effect based on these mechanisms.

Abstract

In the context of chirality induced spin selectivity effect, it has been argued that a chiral molecule when adsorbed on a metal facilitates the formation of a local spin moment at the interface between the metal and molecule, given a strong spin-orbit coupling in the metal. The possibility for such spin moment formation is analyzed in terms of general arguments and effective modeling of a pertinent set-up. The conclusion from this analysis is that a strong spin-orbit coupling in the metal does not provide a sufficient mechanism to sustain a stabilized spin moment at the interface. It is, moreover, shown that an electron flux in to or out from the molecule does not provide conditions for a spin moment formation, regardless of whether the flux is spin-polarized or not.