Publications by Christian Wäckerlin

2D Metalorganic Ferromagnets

Low-dimensional materials exhibiting stable magnetic ordering are interesting from a fundamental point of view as well as for future application in information technologies. Metalorganic magnets, created by linking metal atoms with specific organic molecul ...

WILEY2025

An aperiodic chiral tiling by topological molecular self-assembly

Christian Wäckerlin

Studying the self-assembly of chiral molecules in two dimensions offers insights into the fundamentals of crystallization. Using scanning tunneling microscopy, we examine an uncommon aggregation of polyaromatic chiral molecules on a silver surface. Dense p ...

Nature Research2025

Controlling On-Surface Photoactivity: The Impact of π-Conjugation in Anhydride-Functionalized Molecules on a Semiconductor Surface

Karl-Heinz Ernst, Christian Wäckerlin

On-surface synthesis has become a prominent method for growing low-dimensional carbon-based nanomaterials on metal surfaces. However, the necessity of decoupling organic nanostructures from metal substrates to exploit their properties requires either trans ...

Wiley-VCH Verlag GmbH2024

Light-Controlled Multiconfigurational Conductance Switching in a Single 1D Metal-Organic Wire

Christian Wäckerlin

Precise control of multiple spin states on the atomic scale presents a promising avenue for designing and realizing magnetic switches. Despite substantial progress in recent decades, the challenge of achieving control over multiconfigurational reversible s ...

Amer Chemical Soc2024

Switching the on-surface orientation of oxygen-functionalized helicene

Karl-Heinz Ernst, Christian Wäckerlin, Jan Voigt

Helicenes represent an important class of chiral organic material with promising optoelectronic properties. Hence, functionalization of surfaces with helicenes is a key step toward new organic materials devices. The deposition of a heterohelicene containin ...

Wiley2024

Self-Assembly of N-Rich Triimidazoles on Ag(111): Mixing the Pleasures and Pains of Epitaxy and Strain

Ulrich Aschauer, Christian Wäckerlin, Xing Wang, Mehdi Heydari

In the present report, homochiral hydrogen-bonded assemblies of heavily N-doped (C9H6N6) heterocyclic triimidazole (TT) molecules on an Ag(111) substrate were investigated using scanning tunneling microscopy (STM) and low energy electron diffraction (LEED) ...

Amer Chemical Soc2023

CVD of MoS2 single layer flakes using Na2MoO4 – impact of oxygen and temperature–time-profile

Christian Wäckerlin

Two-dimensional (2D) materials are of great interest in many fields due to their astonishing properties at an atomic level thickness. Many fundamentally different methods to synthesize 2D materials, such as exfoliation or chemical vapor deposition (CVD), h ...

Royal Society of Chemistry (RSC)2023

CVD of MoS2 single layer flakes using Na2MoO4 - impact of oxygen and temperature-time-profile

Andreas Stemmer, Christian Wäckerlin

Two-dimensional (2D) materials are of great interest in many fields due to their astonishing properties at an atomic level thickness. Many fundamentally different methods to synthesize 2D materials, such as exfoliation or chemical vapor deposition (CVD), h ...

Royal Soc Chemistry2023

Correlation between Electronic Configuration and Magnetic Stability in Dysprosium Single Atom Magnets

Harald Brune, Pietro Gambardella, Stefano Rusponi, Marina Pivetta, Edgar Fernandes, Jean-Guillaume De Groot, Fabio Donati, Aparajita Singha, Jan Gui-Hyon Dreiser, Christian Wäckerlin, Romana Baltic

Single atom magnets offer the possibility of magnetic information storage in the most fundamental unit of matter. Identifying the parameters that control the stability of their magnetic states is crucial to design novel quantum magnets with tailored proper ...

AMER CHEMICAL SOC2021

Island formation of Er(trensal) single-ion magnets on graphene observed on the micrometer scale

Jan Gui-Hyon Dreiser, Christian Wäckerlin

We have studied the morphology of Er(trensal) single-ion molecular magnets adsorbed on graphene/Ru(0001) using X-ray photoemission electron microscopy (X-PEEM). By exploiting the elemental contrast at the erbium M-5 edge we observe the formation of molecul ...

2021

Unconventional Spin Relaxation Involving Localized Vibrational Modes in Ho Single-Atom Magnets

Harald Brune, Pietro Gambardella, Stefano Rusponi, Marina Pivetta, Fabio Donati, Aparajita Singha, Jan Gui-Hyon Dreiser, Christian Wäckerlin, Romana Baltic, Katharina Johanna Diller

We investigate the spin relaxation of Ho single atom magnets on MgO/Ag(100) as a function of temperature and magnetic field. We find that the spin relaxation is thermally activated at low field, while it remains larger than 1000 s up to 30 K and 8 T. This ...

AMER PHYSICAL SOC2020

Magnetic properties of on-surface synthesized single-ion molecular magnets

Harald Brune, Stefano Rusponi, Marina Pivetta, Aparajita Singha, Jan Gui-Hyon Dreiser, Christian Wäckerlin, Katharina Johanna Diller

We perform on-surface synthesis of single-ion molecular magnets on an Ag(111) surface and characterize their morphology, chemistry, and magnetism. The first molecule we synthesize is TbPc2 to enable comparison with chemically synthesized and subsequently s ...

2019

Large effect of metal substrate on magnetic anisotropy of Co on hexagonal boron nitride

Harald Brune, Stefano Rusponi, Fabio Donati, Aparajita Singha, Jan Gui-Hyon Dreiser, Christian Wäckerlin, Romana Baltic

We combine x-ray absorption spectroscopy (XAS), x-raymagnetic circular dichroism (XMCD) and x-ray magnetic linear dichroism (XMLD) data with first principles density functional theory (DFT) calculations and amultiorbital many-body Hamiltonian approach to u ...

2019

Understanding the Superior Stability of Single-Molecule Magnets on an Oxide Film

Harald Brune, Stefano Rusponi, Fabio Donati, Aparajita Singha, Jan Gui-Hyon Dreiser, Christian Wäckerlin, Romana Baltic, Katharina Johanna Diller

The stability of magnetic information stored in surface adsorbed single-molecule magnets is of critical interest for applications in nanoscale data storage or quantum computing. The present study combines X-ray magnetic circular dichroism, density function ...

2019

Spin Excitations in a 4f-3d Heterodimer on MgO

Harald Brune, François Patthey, Zeljko Sljivancanin, Donat Fabian Natterer, Fabio Donati, Aparajita Singha, Christian Wäckerlin

We report on the magnetic properties of HoCo dimers as a model system for the smallest intermetallic compound of a lanthanide and a transition metal atom. The dimers are adsorbed on ultrathin MgO(100) films grown on Ag(100). New for 4f elements, we detect ...

AMER PHYSICAL SOC2018

Magnetic properties of single rare-earth atoms on graphene/Ir(111)

Harald Brune, Stefano Rusponi, Marina Pivetta, Fabio Donati, Aparajita Singha, Jan Gui-Hyon Dreiser, Christian Wäckerlin, Romana Baltic

2018

Excited Spin-State Trapping in Spin Crossover Complexes on Ferroelectric Substrates

Harald Brune, Stefano Rusponi, Fabio Donati, Aparajita Singha, Christian Wäckerlin, Romana Baltic

2018

4 f occupancy and magnetism of rare-earth atoms adsorbed on metal substrates

Harald Brune, Pietro Gambardella, Stefano Rusponi, Sebastian Stepanow, Fabio Donati, Aparajita Singha, Jan Gui-Hyon Dreiser, Christian Wäckerlin, Romana Baltic

We report x-ray absorption spectroscopy and x-ray magnetic circular dichroism measurements as well as multiplet calculations for Dy, Ho, Er, and Tm atoms adsorbed on Pt(111), Cu(111), Ag(100), and Ag(111). In the gas phase, all four elements are divalent a ...

Amer Physical Soc2017

Magnetic Hysteresis in Er Trimers on Cu(111)

Harald Brune, Stefano Rusponi, Marina Pivetta, Fabio Donati, Aparajita Singha, Jan Gui-Hyon Dreiser, Christian Wäckerlin, Romana Baltic

We report magnetic hysteresis in Er clusters on. Cu(111) starting from the size-of three atoms. combining Xray magnetic circular dichroism, scanning tunneling microscopy, and mean-field nucleation theory, we determine the size dependent magnetic properties ...

American Chemical Society2016

Magnetic remanence in single atoms

Harald Brune, Pietro Gambardella, François Patthey, Stefano Rusponi, Zeljko Sljivancanin, Edgar Fernandes, Fabio Donati, Aparajita Singha, Jan Gui-Hyon Dreiser, Christian Wäckerlin, Romana Baltic, Katharina Johanna Diller

A permanent magnet retains a substantial fraction of its saturation magnetization in the absence of an external magnetic field. Realizing magnetic remanence in a single atom allows for storing and processing information in the smallest unit of matter. We s ...

American Association for the Advancement of Science2016