Potential Energy Driven Spin Manipulation via a Controllable Hydrogen Ligand

TL;DR

This study demonstrates how a hydrogen-functionalized scanning probe tip can controllably manipulate the spin states of cobalt hydride complexes on a surface by altering their potential energy landscape, enabling precise spin tuning.

Contribution

It introduces a novel method using chemically functionalized tips to manipulate and understand spin transitions in magnetic molecules on surfaces.

Findings

Switching between S=1/2 and S=1 states observed

Total spin change linked to hydrogen position in junction

Chemically functionalized tips effectively tune spin systems

Abstract

Spin-bearing molecules can be stabilized on surfaces and in junctions with desirable properties such as a net spin that can be adjusted by external stimuli. Using scanning probes, initial and final spin states can be deduced from topographic or spectroscopic data, but how the system transitioned between these states is largely unknown. Here we address this question by manipulating the total spin of magnetic cobalt hydride complexes on a corrugated boron nitride surface with a hydrogen- functionalized scanning probe tip by simultaneously tracking force and conductance. When the additional hydrogen ligand is brought close to the cobalt monohydride, switching between a corre- lated S = 1 /2 Kondo state, where host electrons screen the magnetic moment, and a S = 1 state with magnetocrystalline anisotropy is observed. We show that the total spin changes when the system is transferred onto a new potential energy surface defined by the position of the hydrogen in the junction. These results show how and why chemically functionalized tips are an effective tool to manipulate adatoms and molecules, and a promising new method to selectively tune spin systems.