Publications by Jan Gui-Hyon Dreiser

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

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

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

Out-of-Plane Alignment of Er(trensal) Easy Magnetization Axes Using Graphene

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

We have studied Er(trensal) single -ion magnets adsorbed on graphene/Ru(0001), on graphene/Ir(111), and on bare Ru(0001) by scanning tunneling microscopy and X-ray absorption spectroscopy. On graphene, the molecules self -assemble into dense and well -orde ...

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

Molecular lanthanide single-ion magnets: from bulk to submonolayers

Jan Gui-Hyon Dreiser

Single-ion magnets (SIMs) are mononuclear molecular complexes exhibiting slow relaxation of magnetization. They are currently attracting a lot of interest because of potential applications in spintronics and quantum information processing. However, exploit ...

Institute of Physics2015

Interfacial properties of LaMnO3/LaNiO3 superlattices grown along (001) and (111) orientations

Harald Brune, Stefano Rusponi, Jan Gui-Hyon Dreiser

We have employed x-ray absorption spectroscopy and x-ray magnetic circular dichroism (XMCD) at the Ni andMn L-3,L-2 edges in LaMnO3/LaNiO3 superlattices grown along (001) and (111) orientations. Our results show a significant XMCD signal and thus the prese ...

American Physical Society2015

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

Design of Single-Molecule Magnets: Insufficiency of the Anisotropy Barrier as the Sole Criterion

Jan Gui-Hyon Dreiser, Romain Sibille

Determination of the electronic energy spectrum of a trigonalsymtnetry mononuclear Yb3+ single-molecule magnet (SMM) by highresolution absorption and luniinescente spectroscopies reveals that the first excited electronic doublet is placed nearly 500 cm(-1) ...

American Chemical Society2015

Strong antiferromagnetic exchange between manganese phthalocyanine and ferromagnetic europium oxide

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

We report on the antiferromagnetic exchange coupling between a submonolayer of Mn(II)-phthalocyanine molecules and a ferromagnetic Eu(II)-oxide thin film. The exchange energy is larger by nearly two orders of magnitude compared to previous studies involvin ...

Royal Society of Chemistry2015

Cyanide Single-Molecule Magnets Exhibiting Solvent Dependent Reversible "On" and "Off" Exchange Bias Behavior

Jan Gui-Hyon Dreiser

The syntheses, structures, and magnetic properties of four new complex salts, (PPN){Mn-III(salphen)(MeOH)[M-III(CN)(6)]} 7MeOH (Mn2M 7MeOH) (M = Fe, Ru, Os and Co; PPN+ = bis(triphenylphosphoranylidene)ammonium cation; H2salphen = N,N'-bis(salicyliden ...

American Chemical Society2015

The Metallofullerene Field-Induced Single-Ion Magnet HoSc2N@C-80

Jan Gui-Hyon Dreiser

The low-temperature magnetic properties of the endohedral metallofullerene HoSc2N@C-80 have been studied by superconducting quantum interference device (SQUID) magnetometry. Alternating current (ac) susceptibility measurements reveal that this molecule exh ...

Wiley-Blackwell2014

Cluster-size dependent internal dynamics and magnetic anisotropy of Ho ions in HoM2N@C-80 and Ho2MN@C-80 families (M = Sc, Lu, Y)

Jan Gui-Hyon Dreiser, Yi Zhang

The paramagnetic NMR study of HoM2N@C-80-I-h and Ho2MN@C-80-I-h nitride cluster fullerenes (M = Sc, Lu, Y) reveals strong dependence of Ho-induced paramagnetic shifts (delta(para)) in C-13 NMR spectra on the size of the diamagnetic metal in the cluster. In ...

Royal Society of Chemistry2014

Modifying the properties of 4f single-ion magnets by peripheral ligand functionalisation

Jan Gui-Hyon Dreiser

We study the ligand-field splittings and magnetic properties of three Er-III single-ion magnets which differ in the peripheral ligand sphere but exhibit similar first coordination spheres by inelastic neutron scattering (INS) and SQUID magnetometry. The IN ...

Royal Soc Chemistry2014