Publications by Pietro Gambardella

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

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

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

Complex Magnetic Exchange Coupling between Co Nanostructures and Ni(111) across Epitaxial Graphene

Harald Brune, Pietro Gambardella, François Patthey, Stefano Rusponi, Marina Pivetta, Fabio Donati

We report on the magnetic coupling between isolated Co atoms as well as small Co islands and Ni(111) mediated by an epitaxial graphene layer. X-ray magnetic circular dichroism and scanning tunneling microscopy combined with density functional theory calcul ...

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

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

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

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 Moment and Anisotropy of Individual Co Atoms on Graphene

Harald Brune, Pietro Gambardella, François Patthey, Oleg Yazyev, Quentin Dubout, Fabio Donati, Gabriel Albert Autes

We report on the magnetic properties of single Co atoms on graphene on Pt(111). By means of scanning tunneling microscopy spin-excitation spectroscopy, we infer a magnetic anisotropy of K = -8.1 meV with out-of-plane hard axis and a magnetic moment of 2.2 ...

American Physical Society2013

Oxygen Dissociation by Concerted Action of Di-Iron Centers in Metal-Organic Coordination Networks at Surfaces: Modeling Non-Heme Iron Enzymes

Klaus Kern, Pietro Gambardella, Alexandre Dmitriev, Sebastian Stepanow

The high chemical reactivity of unsaturated metal sites is a key factor for the development of novel devices with applications in sensor engineering and catalysis. It is also central in the research for sustainable energy concepts, e.g., the efficient prod ...

American Chemical Society (ACS)2011

Self-Assembled Nanometer-Scale Magnetic Networks on Surfaces: Fundamental Interactions and Functional Properties

Harald Brune, Klaus Kern, Pietro Gambardella, Stefano Rusponi, Anne Lehnert, Sebastian Stepanow, Sergio Vlaic

Nanomagnets of controlled size, organized into regular patterns open new perspectives in the fields of nanoelectronics, spintronics, and quantum computation. Self-assembling processes on various types of substrates allow designing fine-structured architect ...

Wiley-Blackwell2011

Spin and Orbital Magnetic Moment Anisotropies of Monodispersed Bis(Phthalocyaninato)Terbium on a Copper Surface

Klaus Kern, Pietro Gambardella, Sebastian Stepanow, Stephan Rauschenbach, Violetta Sessi, Tzu-Chun Tseng, Nasiba Abdurakhmanova

The magnetic properties of isolated TbPc2 molecules supported on a Cu(100) surface are investigated by X-ray magnetic circular dichroism at 8 K in magnetic fields up to 5 T. The crystal field and magnetic properties of single molecules are found to be robu ...

2010

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

Harald Brune, Pietro Gambardella, Stefano Rusponi, Anne Lehnert, Géraud Moulas, Markus Etzkorn

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

Magnetism of individual atoms adsorbed on surfaces

Harald Brune, Pietro Gambardella

Magnetic impurities in solids cause manifold changes in their macroscopic properties, such as anomalous low temperature resistance due to Kondo screening, reduction of the superconducting transition temperature due to local suppression of the order paramet ...

Elsevier2009

Double-resonant x-ray and microwave absorption: Atomic spectroscopy of precessional orbital and spin dynamics

Giovanni Boero, Pietro Gambardella, Stefano Rusponi

We show that double-resonance spectra recorded during the simultaneous absorption of x-ray and microwave (MW) photons are a fingerprint of the perturbed electronic configuration of atomic species driven to ferromagnetic resonance. X-ray absorption measurem ...

2009

Supramolecular control of the magnetic anisotropy in two-dimensional high-spin Fe arrays at a metal interface

Harald Brune, Klaus Kern, Pietro Gambardella, Sylvain Clair, Alexandre Dmitriev, Sebastian Stepanow, Magalí Alejandra Lingenfelder

Magnetic atoms at surfaces are a rich model system for solid-state magnetic bits exhibiting either classical(1,2) or quantum(3,4) behaviour. Individual atoms, however, are difficult to arrange in regular patterns(1-5). Moreover, their magnetic properties a ...

Nature Publishing Group2009

Longitudinal detection of ferromagnetic resonance using x-ray transmission measurements

Giovanni Boero, Pietro Gambardella, Stefano Rusponi

We describe a setup for the x-ray detection of ferromagnetic resonance in the longitudinal geometry using element-specific transmission measurements. Thin magnetic film samples are placed in a static magnetic field collinear with the propagation direction ...

American Institute of Physics2009

Element-resolved x-ray ferrimagnetic and ferromagnetic resonance spectroscopy

Giovanni Boero, Pietro Gambardella, Stefano Rusponi, Schahrazede-Lila Mouaziz

Institute of Physics (IoP) and Deutsche Physikalische Gesellschaft2008

High magnetic moments and anisotropies for FexCo1 - x monolayers on Pt(111)

Harald Brune, Pietro Gambardella, Stefano Rusponi, Anne Lehnert, Géraud Moulas, Markus Etzkorn

2008

Surface characterization of MnxGe1-x and CryMnxGe1-x-y dilute magnetic semiconductors

Laurent Claude, Harald Brune, Pietro Gambardella, Stefano Rusponi

We have used x-ray photoemission electron microscopy (XPEEM) and x-ray absorption spectroscopy (XAS) to characterize MnxGe1-x and CryMnxGe1-x-y films grown by molecular beam epitaxy. The surface layers of the as-grown films probed by XPEEM present segregat ...

2007

Structure and magnetism of atomically thin Fe layers on flat and vicinal Pt surfaces

Harald Brune, Klaus Kern, Pietro Gambardella, Stefano Rusponi, Violetta Sessi

Ultrathin Fe films on Pt substrates have been investigated under ultrahigh vacuum conditions by scanning tunneling microscopy, low energy electron diffraction, magneto-optical Kerr effect, x-ray magnetic circular dichroism measurements, and Kerr microscopy ...

2006

Finite-sized Heisenberg chains and magnetism of one-dimensional metal systems

Pietro Gambardella

2006