Magnetoresistance through a single molecule

TL;DR

This study demonstrates that integrating a nonmagnetic molecule into a molecular junction can significantly enhance magnetoresistance, advancing the field of molecular spintronics with experimental and theoretical insights.

Contribution

The paper presents the first experimental and theoretical investigation of spin transport through a molecular GMR junction with a nonmagnetic molecule, showing a tenfold increase in magnetoresistance.

Findings

Magnetoresistance increased to 52% with H2Pc molecule

Experimental and theoretical analysis of spin transport

Nonmagnetic molecules can enhance GMR effects

Abstract

The use of single molecules to design electronic devices is an extremely challenging and fundamentally different approach to further downsizing electronic circuits. Two-terminal molecular devices such as diodes were first predicted [1] and, more recently, measured experimentally [2]. The addition of a gate then enabled the study of molecular transistors [3-5]. In general terms, in order to increase data processing capabilities, one may not only consider the electron's charge but also its spin [6,7]. This concept has been pioneered in giant magnetoresistance (GMR) junctions that consist of thin metallic films [8,9]. Spin transport across molecules, i.e. Molecular Spintronics remains, however, a challenging endeavor. As an important first step in this field, we have performed an experimental and theoretical study on spin transport across a molecular GMR junction consisting of two ferromagnetic electrodes bridged by a single hydrogen phthalocyanine (H2Pc) molecule. We observe that even though H2Pc in itself is nonmagnetic, incorporating it into a molecular junction can enhance the magnetoresistance by one order of magnitude to 52%.