Magnetoresistance effect based on spin-selective transport in nanodevices using chiral molecules

TL;DR

This paper demonstrates the fabrication of nanodevices using chiral molecules that exhibit magnetoresistance effects due to spin-selective transport, potentially enabling low-field magnetic sensing applications.

Contribution

It introduces a novel nanofabrication method for CISS-based devices and provides experimental evidence of MR effects at room temperature under low magnetic fields.

Findings

Successful synthesis of a new chiral molecule S-BTBT-CONHR.

Observation of high spin selectivity in thin films via mc-AFM.

Detection of MR effect in nanodevices at room temperature under low magnetic fields.

Abstract

Recently, chirality-induced spin selectivity (CISS) has been observed in chiral molecules and is attractive for application in magnetoresistance (MR) devices. In this study, we fabricate CISS-based nanodevices consisting of chiral molecules sandwiched between Ni78Fe22 and Au electrodes. Prior to device fabrication, we have synthesized the chiral molecule N-(3S)-3,7-dimethyloctyl[1]benzothieno[3,2-b]benzothiophene-2-carboxyamide (S-BTBT-CONHR) and established a method for fabricating nanodevice electrodes. We have successfully observed a high degree of spin selectivity in S-BTBT-CONHR thin films using magnetic conductive atomic force microscopy (mc-AFM). By combining chiral molecules with our advanced nanofabrication technique, we have successfully fabricated Au/S-BTBT-CONHR/Ni78Fe22 nanodevices and observed the MR effect in the fabricated devices under a low magnetic field at room temperature. These MR curves correspond to the magnetization states of the Ni78Fe22 electrode, indicating that the CISS-based MR effect is successfully observed in the nanodevices under a low magnetic field. This study can lead to the development of CISS-based MR devices under low magnetic fields and provide new insights into the CISS effect mechanism on devices.