The spinterface mechanism for the chiral-induced spin selectivity effect: A Critical Perspective

TL;DR

This paper critically examines the spinterface mechanism as a unifying theoretical explanation for the chiral-induced spin selectivity (CISS) effect, addressing open questions and comparing it with other models to advance understanding in spintronics and molecular electronics.

Contribution

It provides a comprehensive critical analysis of the spinterface model, demonstrating its ability to reproduce experimental data and addressing key criticisms and open questions.

Findings

Spinterface model quantitatively reproduces experimental CISS data.

Addresses criticisms regarding surface magnetism and dissipation.

Proposes falsifiable predictions to guide future research.

Abstract

The chiral-induced spin selectivity (CISS) effect, whereby chiral molecules preferentially transmit electrons of one spin orientation, remains one of the most intriguing and debated phenomena at the interface of spintronics, molecular electronics, and quantum materials. Despite extensive experimental observations across diverse platforms - including transport junctions, photoemission, and enantioselective chemistry - a comprehensive theoretical framework is still lacking. In this perspective, we critically examine the spinterface mechanism as a unifying explanation for the CISS effect. The spinterface model, which hypothesizes a feedback interaction between electron motion in chiral molecules and fluctuating surface magnetic moments, is shown to quantitatively reproduce experimental data across various systems and conditions. We contrast it with some existing theoretical models, highlighting key experimental features. Importantly, we also address open questions and criticisms of this model, including the nature of surface magnetism, the role of dissipation, and the applicability of the mechanism to non-helical or electrode-free systems. By offering falsifiable predictions and reconciling theory with experimental raw data, this work aims to sharpen the dialogue surrounding the microscopic origin of CISS and stimulate further experimental and theoretical progress.