# Tuning non-collinear magnetic states by hydrogenation

## TL;DR

This study demonstrates that hydrogenation can modify the symmetry of non-collinear magnetic states in Fe monolayers on Ir(111), enabling control over magnetic structures without altering the substrate.

## Contribution

It shows how hydrogenation induces specific superstructures that alter the magnetic states in ultrathin Fe films, a novel method for magnetic state tuning.

## Key findings

- Hydrogenation creates distinct superstructures in Fe monolayers.
- Magnetic states are modified to follow superstructure symmetry.
- Magnetic state symmetry can be tuned without changing the substrate.

## Abstract

Two different superstructures form when atomic H is incorporated in the Fe monolayer on Ir(111). Depending on the amount of H provided, either a highly ordered p(2x2) hexagonal superstructure or an irregular roughly square structure is created. We present here spin-polarized scanning tunneling microscopy (SP-STM) measurements which reveal that in both cases the magnetic nanoskyrmion lattice state of the pristine Fe monolayer is modified. Our measurements of the magnetic states in these hydrogenated films are in agreement with superpositions of cycloidal spin spirals which follow the pattern and the symmetry dictated by the H superstructures. We thus demonstrate here the possibility to vary the symmetry of a non-collinear magnetic state in an ultrathin film without changing its substrate.