Spin Manipulation by Creation of Single-Molecule Radical Cations

TL;DR

This study demonstrates the reversible creation and manipulation of localized spins in single-molecule radical cations of all-trans-retinoic acid on a gold surface, using scanning tunneling microscopy and spectroscopy.

Contribution

It reveals a new method to control molecular spin states through electron abstraction, advancing single-molecule spintronics.

Findings

Single ReA molecules can be switched between multiple states with localized spins.

ReA on Au can be converted into radical cations by electron abstraction.

Localized spins in ReA are reversible and do not affect neighboring molecules.

Abstract

All-trans-retinoic acid (ReA), a closed-shell organic molecule comprising only C, H, and O atoms, is investigated on a Au(111) substrate using scanning tunneling microscopy and spectroscopy. In dense arrays single ReA molecules are switched to a number of states, three of which carry a localized spin as evidenced by conductance spectroscopy in high magnetic fields. The spin of a single molecule may be reversibly switched on and off without affecting its neighbors. We suggest that ReA on Au is readily converted to a radical by the abstraction of an electron.