Detecting chirality in two-terminal electronic devices

TL;DR

This paper uncovers fundamental mechanisms behind magnetoresistance in two-terminal chiral electronic devices, revealing how CISS can be detected in both nonlinear and linear regimes, guiding future spintronic device design.

Contribution

It introduces a new understanding of MR generation in nonlinear response and proposes methods to detect CISS in linear response without magnetic materials.

Findings

MR depends on chirality, charge type, and bias direction

CISS can be detected via spin-valve or Hanle precession in linear regime

Guidelines for designing chirality-based spintronic devices

Abstract

Central to spintronics is the interconversion between electronic charge and spin currents, and this can arise from the chirality-induced spin selectivity (CISS) effect. CISS is often studied as magnetoresistance (MR) in two-terminal (2T) electronic devices containing a chiral (molecular) component and a ferromagnet. However, fundamental understanding of when and how this MR can occur is lacking. Here, we uncover an elementary mechanism that generates such a MR for nonlinear response. It requires energy-dependent transport and energy relaxation within the device. The sign of the MR depends on chirality, charge carrier type, and bias direction. Additionally, we reveal how CISS can be detected in the linear response regime in magnet-free 2T devices, either by forming a chirality-based spin-valve using two or more chiral components, or by Hanle spin precession in devices with a single chiral component. Our results provide operation principles and design guidelines for chirality-based spintronic devices and technologies.