A5049785739- Molecular Junctions and Nanostructures
- Quantum and electron transport phenomena
- Advanced Chemical Physics Studies
- Surface Chemistry and Catalysis
- Surface and Thin Film Phenomena
- Force Microscopy Techniques and Applications
- Magnetic properties of thin films
- Graphene research and applications
- Atomic and Molecular Physics
- Physics of Superconductivity and Magnetism
- Spectroscopy and Quantum Chemical Studies
- Semiconductor materials and devices
- Machine Learning in Materials Science
- Porphyrin and Phthalocyanine Chemistry
- Advancements in Semiconductor Devices and Circuit Design
- Quantum, superfluid, helium dynamics
- Electronic and Structural Properties of Oxides
- Mechanical and Optical Resonators
- Topological Materials and Phenomena
- Nanowire Synthesis and Applications
- Electron and X-Ray Spectroscopy Techniques
- Advanced Materials Characterization Techniques
- Magnetism in coordination complexes
- nanoparticles nucleation surface interactions
- Ion-surface interactions and analysis
Donostia International Physics Center
2016-2025
Material Physics Center
2016-2025
University of Duisburg-Essen
2023
University of the Basque Country
2019-2023
Center for Quantum Nanoscience
2023
Institute for Basic Science
2023
PLUS Foundation
2023
Ewha Womans University
2023
Ayuntamiento de San Sebastián
2020
Ikerbasque
2016-2019
In molecular spintronics, the spin state of a molecule may be switched on and off by changing structure. Here, we switch double-decker bis(phthalocyaninato)terbium(III) complex (TbPc2) adsorbed an Au(111) surface applying electric current via scanning tunnelling microscope. The dI/dV curve recorded onto TbPc2 shows Kondo peak, origin which is unpaired π-orbital phthalocyaninato (Pc) ligand. By controlled pulses, could rotate upper Pc ligand in TbPc2, leading to disappearance reappearance...
We present novel methods implemented within the non-equilibrium Green function code (NEGF) transiesta based on density functional theory (DFT). Our flexible, next-generation DFT–NEGF handles devices with one or multiple electrodes (Ne≥1) individual chemical potentials and electronic temperatures. describe its for electrostatic gating, contour optimizations, assertion of charge conservation, as well newly algorithms optimized scalable matrix inversion, performance-critical pivoting, hybrid...
We present a systematic investigation of molecule-metal interactions for transition-metal phthalocyanines (TMPc, with TM = Fe, Co, Ni, Cu) adsorbed on Ag(100). Scanning tunneling spectroscopy and density functional theory provide insight into the charge transfer hybridization mechanisms TMPc as function increasing occupancy 3$d$ metal states. show that all four receive approximately one electron from substrate. Charge occurs substrate to molecules, inducing reorganization in FePc CoPc, while...
We have carried out a density functional study of vibrationally inelastic tunneling in the scanning microscope acetylene on copper. Our approach is based many-body generalization Tersoff-Hamann theory. explain why only carbon-hydrogen stretch modes are observed terms and elastic contributions to conductance. The found be efficient highly localized space without any resonant interaction governed by vibration-induced change amplitude.
We present a method for including inelastic scattering in first-principles density-functional computational scheme molecular electronics. As an application, we study two geometries of four-atom gold wires corresponding to different values strain, and results nonlinear differential conductance vs. device bias. Our theory is quantitative agreement with experimental results, explains the experimentally observed mode selectivity. also identify signatures phonon heating.
We present a method to analyze the results of first-principles based calculations electronic currents including inelastic electron-phonon effects. This allows us determine and vibrational symmetries in play, hence obtain so-called propensity rules for studied systems. show that only few scattering states---namely those belonging most transmitting eigenchannels---need be considered complete description electron transport. apply on four different systems each case.
The adsorption of a molecular electron donor on Au(111) is characterized by the spontaneous formation superlattice monomers spaced several nanometers apart. coverage-dependent pair distributions obtained from scanning tunneling microscopy data reveal an intermolecular long-range repulsive potential, which decreases as inverse separation. Density functional theory calculations show charge accumulation in molecules due to donation into metal. Our results suggest that electrostatic repulsion...
Silicon nanowires grown along the 100 direction with a bulk Si core are studied density-functional calculations. Two surface reconstructions prevail after exploration of large fraction phase space nanowire reconstructions. Despite their energetical equivalence, one is found to be strongly metallic while other semimetallic. This electronic-structure behavior dictated by particular states each reconstruction. These results imply that doping not required in order obtain good conducting nanowires.
Low-dimensional physical systems are characterized by unusual behavior due to strong quantum fluctuations and electron-electron interactions which arise from the confinement of electrons. The capability tuning geometry one-dimensional (1D) is an opportunity test limits systems. In this Colloquium physics 1D spin chains on surfaces discussed experimental theoretical points view. Also opportunities in emerging areas research such as computation communication spintronics.
We study the electronic mechanisms underlying induction and propagation of chirality in achiral molecules deposited on surfaces. Combined scanning tunneling microscopy ab initio structure calculations Cu-phthalocyanines adsorbed Ag(100) reveal formation chiral molecular orbitals structurally undistorted molecules. This effect shows that can be manifest exclusively at level due to asymmetric charge transfer between substrate. Single molecule correlates with attractive van der Waals...
Abstract A magnetic atom inside a superconductor locally distorts superconductivity. It scatters Cooper pairs as potential with broken time-reversal symmetry, leading to localized bound states subgap excitation energies, named Shiba states. Most conventional approaches regarding treat impurities point scatterers isotropic exchange interaction. Here, we show that the number and shape of are correlated spin-polarized atomic orbitals impurity, hybridized superconductor. Using scanning...
This article reviews manipulation of single molecules by scanning tunnelling microscopes, in particular vertical manipulation, lateral and inelastic electron (IET) manipulation. For a better understanding these processes, we shortly review imaging microscopy – as prerequisite to detect the manipulated species verify result well spectroscopy IET which are used chemically identify before after that employs current.
Recent advances in scanning probe techniques rely on the chemical functionalization of probe-tip termination by a single molecule. The success this approach opens tantalizing prospect introducing spin sensitivity through magnetic Here, we use nickelocene-terminated tip (Nc-tip), which offers possibility producing excitations apex tunneling microscope (STM). We show that when Nc-tip is hundred pm away from point contact with surface-supported object, effects may be probed changes excitation...
A combined experimental and theoretical study is presented for the C-D stretch mode excitation of acetylene isotopes, C2HD C2D2, on Cu(100) via inelastic electron tunneling (IET) in a scanning microscope junction. The calculated IET images using density functional theory show that measured signal from C2D2 derives antisymmetric mode. Selection rules are derived involve constraint imposed by image symmetry characters vibrational adsorbate-induced states at Fermi level.
The contribution of conduction electrons to the Auger neutralization rate a slow ion at metal surface has been calculated. We have considered scattering ${\mathrm{He}}^{+}$ on Al and studied effect potential rate. This accomplished by taking into account modification wave function captured electron induced presence ion. is shown increase also calculated deexcitation ${\mathrm{He}}^{*} (n=2)$ atoms in front an aluminum surface, including distorsion created atom states. In this case, reduced...
An electronic band with quasi-one-dimensional dispersion is found at the interface between a monolayer of charge-transfer complex (TTF-TCNQ) and Au(111) surface. Combined local spectroscopy numerical calculations show that results from mixing metal molecular states. The layer folds underlying states mixes them selectively, through TTF component, giving rise to anisotropic hybrid bands. Our suggest that, by tuning components such layers, dimensionality organic-metal can be engineered.
The excitation of the spin degrees freedom an adsorbed atom by tunneling electrons is computed using strong coupling theory. Recent measurements [Heinrich, Science 306, 466 (2004)] reveal that electron currents in a magnetic system efficiently excite its moments. Our theory shows incoming strongly couples with adsorbate so memory initial state lost, leading to large efficiencies. First-principles transmissions are evaluated quantitative agreement experiment.
The properties of the (111) surfaces Cu, Ag, and Au are evaluated using a first-principles approach with strictly localized basis sets. These present metallic extended that priori difficult to describe local-basis approach. We explore methodologies enhance sets surface atoms in order accurately such as energies, states, work functions. In this way, advantages computations (namely, efficiency, optimum size scaling, natural description bonding real space) can be retained, while keeping...
The active control of a molecular spin represents one the main challenges in spintronics. Up to now manipulation has been achieved through modification structure either by chemical doping or external stimuli. However, molecule adsorbed on surface depends primarily interaction between its localized orbitals and electronic states substrate. Here we change effective single modifying molecule/metal interface controlled way using low-temperature scanning tunneling microscope. A nickelocene...
Inelastic electron tunneling spectroscopy (IETS) within the junction of a scanning microscope (STM) uses current-driven spin-flip excitations for an all-electrical characterization spin state single object. Usually decoupling layers between object, atom or molecule, and supporting surface are needed to observe these excitations. Here we study magnetism sandwich nickelocene molecule (Nc) adsorbed directly on Cu(100) by means X-ray magnetic circular dichroism (XMCD) density functional theory...
We show that the magnetic ordering of coupled atomic dimers on a superconductor is revealed by their intragap spectral features. Chromium atoms $\ensuremath{\beta}\text{\ensuremath{-}}{\mathrm{Bi}}_{2}\mathrm{Pd}$ surface display Yu-Shiba-Rusinov bound states, detected as pairs excitations in tunneling spectra. By means manipulation with scanning microscope's tip, we form Cr different arrangements and find features appear either shifted or split respect to single atoms. These variations are...