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Harald Brune

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Related publications (117)

Page 3 of 6

The role of magnetic anisotropy in the Kondo effect

Harald Brune, Markus Ternes

In the Kondo effect, a localized magnetic moment is screened by forming a correlated electron system with the surrounding conduction electrons of a non-magnetic host1. Spin S D 1=2 Kondo systems have been investigated extensively in theory and experiments, ...

Nature Publishing Group2008

Origin of Perpendicular Magnetic Anisotropy and Large Orbital Moment in Fe Atoms on MgO

Harald Brune, Stefano Rusponi, Marina Pivetta, Jan Gui-Hyon Dreiser, Pietro Gambardella, Fabio Donati, Luca Gragnaniello, Giulia Elisabetta Pacchioni

We report on the magnetic properties of individual Fe atoms deposited on MgO(100) thin films probed by x-ray magnetic circular dichroism and scanning tunneling spectroscopy. We show that the Fe atoms have strong perpendicular magnetic anisotropy with a zer ...

American Physical Society2015

Magnetic remanence in single atoms

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

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

Engineering atomic-scale magnetic fields by dysprosium single atom magnets

Harald Brune, Tobias Bilgeri

Atomic scale engineering of magnetic fields is a key ingredient for miniaturizing quantum devices and precision control of quantum systems. This requires a unique combination of magnetic stability and spin-manipulation capabilities. Surface-supported singl ...

Nature Portfolio2021

Electrically driven spin resonance of 4f electrons in a single atom on a surface

Harald Brune

A pivotal challenge in quantum technologies lies in reconciling long coherence times with efficient manipulation of the quantum states of a system. Lanthanide atoms, with their well-localized 4f electrons, emerge as a promising solution to this dilemma if ...

Nature Research2024

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

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

Adsorption sites of individual metal atoms on ultrathin MgO(100) films

Harald Brune, François Patthey, Fabio Donati, Edgar Fernandes

We use Ca doping during growth of one- and two-monolayer-thick MgO films on Ag(100) to identify the adsorption sites of individual adatoms with scanning tunnelingmicroscopy. For thiswe combine atomic resolution images of the bare MgO layer with images of t ...

Amer Physical Soc2017

Uniform magnetic properties for an ultrahigh-density lattice of noninteracting Co nanostructures

Harald Brune, Stefano Rusponi, Nicolas Weiss

We report on the magnetic properties of two-dimensional Co nanoparticles arranged in macroscopically phase-coherent superlattices created by self-assembly on Au(788). Our particles have a density of 26 Tera/in(2) (1 Tera=10(12)), are monodomain, and have u ...

2005

An Endohedral Single-Molecule Magnet with Long Relaxation Times: DySc_{2}N@C_{80}

Harald Brune, Stefano Rusponi, Jan Gui-Hyon Dreiser

The magnetism of DySc2N@C80 endofullerene was studied with X-ray magnetic circular dichroism (XMCD) and a magnetometer with a superconducting quantum interference device (SQUID) down to temperatures of 2 K and in fields up to 7 T. XMCD shows hysteresis of ...

2012

Low Temperature Ferromagnetism in Chemically Ordered FeRh Nanocrystals

Harald Brune, Stefano Rusponi, Jan Gui-Hyon Dreiser, Sergio Vlaic, Alberto Cavallin

In sharp contrast to previous studies on FeRh bulk, thin films, and nanoparticles, we report the persistence of ferromagnetic order down to 3 K for size-selected 3.3 nm diameter nanocrystals embedded into an amorphous carbon matrix. The annealed nanopartic ...

Amer Physical Soc2013

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

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

Direct Electrical Access to the Spin Manifolds of Individual Lanthanide Atoms

Harald Brune

Lanthanide atoms show long magnetic lifetimes because of their strongly localized 4f electrons, but electrical control of their spins has been difficult because of their closed valence shell configurations. We achieved electron spin resonance of individual ...

AMER CHEMICAL SOC2025

Reverse Spillover Dominating CO Adsorption on Single Cobalt Atoms in Graphene Divacancies

Harald Brune, Francesco Armillotta, Pardis Naderasli

The kinetics of molecular adsorption and desorption can unveil the details of the adsorption potential that impact, for instance, the overall sticking probability. This information is of particular importance for catalysis and gas sensing. We investigate t ...

2024

Antiferromagnetic MnNi tips for spin-polarized scanning probe microscopy

Harald Brune, François Patthey, Donat Fabian Natterer, Tobias Bilgeri

Spin-polarized scanning tunneling microscopy (SP-STM) measures magnetoresistance with atomic resolution. While various methods for achieving SP probes have been developed, each is limited with respect to fabrication, performance, and operating conditions. ...

AMER INST PHYSICS2018

Combined ARPES and STM study of Pb/Au(111) Moiré structure: One overlayer, two symmetries

Klaus Kern, Harald Brune, Marco Grioni, Alberto Crepaldi, Emmanouil Frantzeskakis

The structural and electronic properties of a Pb monolayer (ML) grown on Au(111) are investigated by scanning tunneling microscopy (STM) and angle resolved photoelectron spectroscopy (ARPES). We find an incommensurate Moire structure with an approximate (5 ...

Amer Physical Soc2013

Magnetocrystalline anisotropy energy of Co and Fe adatoms on the (111) surfaces of Pd and Rh

Harald Brune, Stefano Rusponi, Pietro Gambardella, Anne Lehnert

We performed a combined theoretical and experimental investigation of the orbital magnetism and magnetocrystalline anisotropy of isolated Co and Fe adatoms on Pd(111) and Rh(111). Theoretical calculations of the spin and orbital moments are based on ab ini ...

2010

Surface-Confined Self-Assembly of Di-carbonitrile Polyphenyls

Harald Brune, Uta Schlickum, Régis Decker

This Feature Article reports on the controlled formation and structure-functionality aspects of vacuum-deposited self-assembled organic and metal-organic networks at metal surfaces using ditopic linear and nonlinear molecular bricks, namely di-carbonitrile ...

Wiley-Blackwell2011

Quantifying residual hydrogen adsorption in low-temperature STMs

Harald Brune, François Patthey, Donat Fabian Natterer

We report on low-temperature scanning tunneling microscopy observations demonstrating that individual Ti atoms on hexagonal boron nitride dissociate and adsorb hydrogen without measurable reaction barrier. The clean and hydrogenated states of the adatoms a ...

Elsevier2013

Magnetic anisotropy of Fe and Co adatoms and Fe clusters magnetically decoupled from Ni_{3}Al(111) by an alumina bilayer

Harald Brune, Stefano Rusponi, Anne Lehnert

The magnetic properties of individual Fe and Co atoms as well as of small Fe clusters adsorbed on two atomic layers of Al2O3 grown on Ni3Al(111) have been investigated by x-ray absorption spectroscopy and x-ray magnetic circular dichroism. We find ratios o ...

2010

Thermal dynamics at surfaces

Harald Brune

The present paper describes what happens at the surface of a crystal as its temperature steadily increases from zero Kelvin close to the bulk melting temperature. We treat thermal motion, such as the diffusion of individual adatoms establishing mass transp ...

Wiley-Blackwell2009