A5002561057- Quantum and electron transport phenomena
- Magnetic properties of thin films
- Molecular Junctions and Nanostructures
- Surface and Thin Film Phenomena
- Quantum Information and Cryptography
- Quantum optics and atomic interactions
- Advanced Chemical Physics Studies
- Atomic and Subatomic Physics Research
- Quantum Mechanics and Applications
- Quantum Computing Algorithms and Architecture
- Topological Materials and Phenomena
- Virtual Reality Applications and Impacts
- Interactive and Immersive Displays
- Physics of Superconductivity and Magnetism
- Graphene research and applications
- Force Microscopy Techniques and Applications
- Spectroscopy and Quantum Chemical Studies
- Cold Atom Physics and Bose-Einstein Condensates
- Mechanical and Optical Resonators
- Advanced Electron Microscopy Techniques and Applications
- Magnetism in coordination complexes
- Advanced Memory and Neural Computing
- Advanced Materials Characterization Techniques
- Advanced Condensed Matter Physics
- Augmented Reality Applications
Delft University of Technology
2015-2024
Material Physics Center
2019
Ikerbasque
2019
Donostia International Physics Center
2019
University of Maryland, College Park
2010
National Institute of Standards and Technology
2010
IBM Research - Almaden
2007-2010
Leiden University
2004-2010
Center for Nanoscale Science and Technology
2010
Stanford University
2007
Magnetic anisotropy allows magnets to maintain their direction of magnetization over time. Using a scanning tunneling microscope observe spin excitations, we determined the orientation and strength anisotropies individual iron manganese atoms on thin layer copper nitride. The relative intensities inelastic processes are consistent with dipolar interactions, as seen for neutron scattering. First-principles calculations indicate that magnetic become incorporated into polar covalent surface...
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.
Individual Fe atoms on a Cu2N/Cu(100) surface exhibit strong magnetic anisotropy due to the crystal field. Using atom manipulation in low-temperature STM we demonstrate that of one is significantly influenced by local strain second placed nearby. Depending relative positions two Cu2N lattice can controllably enhance or reduce uniaxial anisotropy. We present model explains observed behavior qualitatively terms first principles.
We investigate the thickness-dependent electronic properties of ultrathin SrIrO_{3} and discover a transition from semimetallic to correlated insulating state below 4 unit cells. Low-temperature magnetoconductance measurements show that spin fluctuations in are significantly enhanced while approaching point. The further studied by scanning tunneling spectroscopy, showing cell is on verge gap opening. Our density functional theory calculations reproduce critical thickness opening requires...
Fast spin flips for entangled atoms The integration of pump-probe spectroscopy with scanning tunneling microscopy (STM) tools has allowed studies relaxation in on the nanosecond time scale. However, following free evolution a pair spins requires faster initial excitation than can be delivered microwave pulses. Veldman et al. sequentially combined electron resonance–STM and direct-current techniques to instantaneously flip while preserving coherence. They used this method follow free,...
Screening the electron spin of a magnetic atom via coupling to conduction electrons results in strong resonant peak density states at Fermi energy, Kondo resonance. We show that another unscreened can split resonance into two peaks. Inelastic excitation spectroscopy with scanning tunneling microscopy is used probe effect Co atom, supported on thin insulating layer Cu substrate, weakly coupled nearby Fe form an inhomogeneous dimer. The by interaction non-Kondo but be reconstituted field...
We reinterpret the microcanonical conditions in quantum domain as constraints for interaction of "gas subsystem" under consideration and its environment ("container"). The time average a purity measure is found to equal over respective path Hilbert space. then show that typical (degenerate or nondegenerate) thermodynamical systems almost all states within allowed region space have local von Neumann entropy S close maximum P minimum, respectively. Typically, should obey second law.
Single-molecule junctions are found to show anomalous spikes in dI/dV spectra. The position energy of the related local vibration mode energies. A model vibrationally induced two-level systems reproduces data very well. This mechanism is expected be quite general for single-molecule junctions. It acts as an intrinsic amplification features and may exploited a new spectroscopic tool.
Abstract A system of two exchange-coupled Kondo impurities in a magnetic field gives rise to rich phase space hosting multitude correlated phenomena. Magnetic atoms on surfaces probed through scanning tunnelling microscopy provide an excellent platform investigate coupled impurities, but typical high temperatures prevent field-dependent studies from being performed, rendering large parts the inaccessible. We present study pairs Co insulating Cu 2 N/Cu(100), which each have temperature only...
The inelastic portion of the tunnel current through an individual magnetic atom grants unique access to read out and change atom's spin state, but it also provides a path for spontaneous relaxation decoherence. Controlled closure channel would allow latter be switched off at will, paving way coherent manipulation in single atoms. Here we demonstrate complete channels both orbital transitions due controlled geometric modification environment, using scanning tunnelling microscopy (STM)....
The interaction of electrons with a periodic potential atoms in crystalline solids gives rise to band structure. structure existing materials can be measured by photoemission spectroscopy and accurately understood terms the tight-binding model, however not many experimental approaches exist that allow tailor artificial crystal lattices using bottom-up approach. ability engineer study atomically crafted designer scanning tunnelling microscopy (STM/STS) helps understand emergence material...
Low-dimensional quantum magnetism presents a seemingly unlimited source of rich, intriguing physics. Yet, because realistic experimental representations are difficult to come by, the field remains predominantly theoretical. In recent years, artificial spin structures built through manipulation magnetic atoms in scanning tunnelling microscope have developed into promising testing ground for verification theoretical models. Here, we present an overview available tools and discuss achievements...
Historically, electron spin resonance (ESR) has provided excellent insight into the electronic, magnetic, and chemical structure of samples hosting centers. In particular, hyperfine interaction between nuclear spins yields valuable structural information about these recent years, combination ESR scanning tunneling microscopy (ESR-STM) allowed to acquire such individual centers magnetic atoms bound atop a surface, while additionally providing spatial binding site. Here, we conduct full...
The formation of gold nanowires in vacuum at room temperature reveals a periodic spectrum exceptionally stable diameters. This is identified as shell structure similar to that which was recently discovered for alkali metals low temperatures. present two competing ``magic'' series diameters, one governed by electronic and the other atomic packing.
The oscillatory voltage dependence of the conductance a quantum point contact in presence single pointlike defect has been analyzed theoretically. Such signals are detectable and may be exploited to obtain information on positions below metal surface. Both tunnel junctions ballistic contacts adiabatic shape have considered. effect interference taken into account between principal wave that is directly transmitted through partial scattered by defect. This leads oscillations as function...
Abstract The orbital angular moment of magnetic atoms adsorbed on surfaces is often quenched as a result an anisotropic crystal field. Due to spin-orbit coupling, what remains the typically delineates orientation electron spin. These two effects limit scope information processing based these essentially only one degree freedom: In this work, we gain independent access both spin and degrees freedom single atom, inciting probing excitations each moment. By coordinating Fe atom atop nitrogen...
In a previous paper [Avotina et al., Phys. Rev. B 71, 115430 (2005)] we have shown that in principle it is possible to image the defect positions below metal surface by means of scanning tunneling microscope. The relies on interference electron waves scattered defects, which give rise small but measurable conductance fluctuations. Whereas work band structure was assumed be free-electron like, here investigate effects Fermi anisotropy. We demonstrate amplitude and period oscillations are...