We present local density-functional results for structural and electronic properties of ${\mathrm{Al}}_{2}{\mathrm{O}}_{3}(0001)$, clean with Pt Ag adsorption. Significant surface relaxations penetrate to the third oxygen layer, 5.2 \AA{} below surface. The dominant mechanism metal adhesion is polarization relatively weak ( $\ensuremath{\simeq}0.4$ 0.6 eV/atom Pt, respectively); however, isolated atoms bind up $5\ifmmode\times\else\texttimes\fi{}$ as strongly an ionic bond induced by...

Crystal graph attention networks speed up the prediction of new thermodynamically stable materials in high-throughput searches.

A deeper understanding of the differences between quantum and classical dynamics promises great potential for emerging technologies. Nevertheless, some aspects remain poorly understood, particularly concerning role coherence in open systems. On one hand, leads to entanglement even nonlocality. other, it may lead a suppression fluctuations, causing violations thermokinetic uncertainty relations (TUR KUR) that are valid processes. These represent two different manifestations coherence,...

The role of the discontinuity exchange-correlation potential density functional theory is studied in context electron transport and shown to be intimately related Coulomb blockade. By following time evolution an interacting nanojunction attached biased leads, we find that, instead evolving a steady state, system reaches dynamical state characterized by correlation-induced current oscillations. Our results establish picture blockade manifesting itself as periodic sequence charging discharging...

We illustrate the scope of time-dependent density-functional theory for strongly correlated (lattice) models out equilibrium. Using exact many-body time evolution, we reverse engineer exchange correlation (xc) potential ${v}_{\mathrm{xc}}$ small Hubbard chains exposed to fields. introduce an adiabatic local density approximation 1D model and compare it results, gain insight about approximate xc potentials. Finally, provide some remarks on $v$-representability model.

We study the non-equilibrium dynamics of small, strongly correlated clusters, described by a Hubbard Hamiltonian, propagating in time Kadanoff-Baym equations within Hartree-Fock, 2nd Born, GW and T-matrix approximations. compare results to exact numerical solutions. find that is overall superior other approximations, good agreement with low-density regime. In long limit, many-body approximations attain an unphysical steady state which we attribute implicit inclusion infinite order diagrams...

We present in detail a method we recently introduced [Phys. Rev. Lett. 103, 176404 (2009)] to describe finite systems and out of equilibrium, where the evolution time is performed via Kadanoff-Baym equations within many-body perturbation theory. Our consist small, strongly correlated clusters, described by Hubbard Hamiltonian Hartree-Fock, second Born, $GW$, $T$-matrix approximations. compare results from dynamics those exact numerical solutions. The outcome our comparisons that, among...

Quantum transport of strongly correlated fermions is central interest in condensed matter physics. While the stationary expansion dynamics have recently been measured with cold atoms 2D optical lattices, ab initio simulations limited to 1D setups so far. Here, we present first precise fermionic quantum for and 3D. The are based on nonequilibrium Green functions incorporate strong correlations via $T$-matrix self-energies. predict short-time dynamics, discover a universal scaling velocity...

We introduce a new class of exchange-correlation potentials for static and time-dependent Density Functional Theory strongly correlated systems in 3D. The are obtained via Dynamical Mean Field and, strong enough interactions, exhibit discontinuity at half filling density, signature the Mott transition. For perturbations, dynamics is described adiabatic local density approximation. Results from scheme compare very favorably to exact ones clusters. As an application, we study Bloch...

Hot electron relaxation and transport in nanostructures involve a multitude of ultrafast processes whose interplay relative importance are still not fully understood, but which relevant for future applications areas such as photocatalysis optoelectronics. To unravel these processes, their dynamics both time space must be studied with high spatiotemporal resolution structurally well-defined nanoscale objects. We employ time-resolved photoemission microscopy to image the photogenerated hot...

On several metallic substrates, first-principles density-functional calculations of ${\mathrm{Al}}_{2}{\mathrm{O}}_{3}$ 5--7 \AA{} films predict a structure, stabilized by interfacial electrostatics, which has no bulk counterpart. In two and three O-layer films, Al ions prefer distorted tetrahedral sites, over the normal octahedral sites. The film/substrate interface is found to consist strongly chemisorbed oxygen determining factor in geometry; these oxygens are only weakly perturbed...

The electronic structure of Pd clusters deposited on polycrystalline graphite has been investigated by x-ray photoemission, Auger spectroscopy, and bremsstrahlung isochromat spectroscopy. Initial- final-state shifts energy levels as a function the average cluster size R are small, but important modifications density filled empty states at Fermi level observed. With decreasing particle size, d portion conduction band broadens to higher while its valence counterpart shows opposite shift. A...

We use the Nonequilibrium Green's Function (NEGF) method to perform real-time simulations of ultrafast electron dynamics photoexcited donor-C60 complexes modeled by a Pariser-Parr-Pople Hamiltonian. The NEGF results are compared mean-field Hartree-Fock (HF) calculations disentangle role correlations. Initial benchmarking against numerically highly accurate time-dependent Density Matrix Renormalization Group verifies accuracy NEGF. then find that charge-transfer (CT) excitons partially decay...

An ab initio quantum-classical mixed scheme for the time evolution of electrode-device-electrode systems is introduced to study nuclear dynamics in quantum transport. Two model are discussed illustrate method. Our results provide first example current-induced molecular desorption as obtained from a full time-dependent approach and suggest use ac biases way tailor electromigration. They also show importance non-adiabatic effects ultrafast phenomena nanodevices.

In this work we include electron-electron interaction beyond Hartree-Fock level in our non-equilibrium Green's function approach by a crude form of GW through the Single Plasmon Pole Approximation. This is achieved treating all conduction band electrons as single effective screening Coulomb potential. We describe corresponding self-energies scheme for multi-subband system. order to apply formalism heterostructures discuss and plasmon dispersion both 2D 3D systems. Results are shown four well...

First principles density functional calculations for adsorption of Ti on ${\mathrm{Al}}_{2}{\mathrm{O}}_{3}(0001)$ indicate that $\mathrm{Ti}:{\mathrm{Al}}_{2}{\mathrm{O}}_{3}(0001)$ interfaces become intermixed. Substitutional replaces a surface Al atom rather than subsurface Al, and the Al-terminated is unstable under adsorption. Adsorbed displaces resulting in mixed Ti/Al interfacial layer instead sharp $\mathrm{Ti}:{\mathrm{Al}}_{2}{\mathrm{O}}_{3}$ interface. Our results provide...

We present a theory of molecular motors based on the Ehrenfest dynamics for nuclear coordinates and adiabatic limit Kadanoff-Baym equations current-induced forces. Electron-electron interactions can be systematically included through many-body perturbation theory, making nonequilibrium Green's functions formulation suitable first-principles treatments realistic junctions. The method is benchmarked against simulations via real-time equations, finding an excellent agreement. Results...

We evaluate several approximations for the self-energy operator and dielectric function of systems interacting electrons using a two-dimensional Hubbard cluster which self-energy, function, one-particle Green's may be calculated exactly. The results show $\mathrm{GW}$ approximation (in form in it is commonly used ab initio calculations real materials) to relatively successful establishing main features spectrum, even when electron-electron interaction not weak. It also clear that improving...

We present reflectance-anisotropy spectroscopy data for the adsorption of 3-thiophene carboxylic acid on clean and $\mathrm{O}(2\ifmmode\times\else\texttimes\fi{}1)/\mathrm{C}\mathrm{u}(110)$ surfaces, which demonstrates sensitivity to orientation parallel perpendicular surface. Electronic structure calculations were performed clarify bonding assign RAS transitions.

We investigate the static and dynamical behavior of one-dimensional interacting fermions in disordered Hubbard chains contacted to semi-infinite leads. The are described via repulsive Anderson-Hubbard Hamiltonian, using time-dependent lattice density-functional theory. our quantum transport system is studied an integration scheme available literature, which we modify recursive Lanczos method increase its efficiency. To quantify degree localization due disorder interactions, adapt definition...

We propose a description of nonequilibrium systems via simple protocol that combines exchange-correlation potentials from density functional theory with self-energies many-body perturbation theory. The approach, aimed to avoid double counting interactions, is tested against exact results in Hubbard-type systems, respect interaction strength, speed and inhomogeneity, system dimensionality size. In many regimes, we find significant improvement over adiabatic time dependent or second Born...

Abstract Magnetic skyrmions are topological excitations of great promise for compact and efficient memory storage. However, to interface skyrmionics with electronic devices requires reliable ways creating destroying such excitations. In this work, we unravel the microscopic mechanism behind ultrafast skyrmion generation by femtosecond laser pulses in transition metal thin films. We employ a theoretical approach based on two-band model, show that exciting itinerant subsystem nucleation can...