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Open AccessQuantum many-body effects on Rydberg excitons in cuprous oxide
We investigate quantum many-body effects on Rydberg excitons in cuprous oxide induced by the surrounding electron-hole plasma. Line shifts and widths are calculated by full diagonalisation of the plasma Hamilt...
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Article
Resonant charge transfer at dielectric surfaces
We report on the theoretical description of secondary electron emission due to resonant charge transfer occurring during the collision of metastable N2(3Σ+ u ) m...
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Article
Determination of sheath parameters by test particles upon local electrode bias and plasma switching
Equilibrating gravitation by electric forces, microparticles can be confined in the plasma sheath above suitably biased local electrodes. Their position depends on the detailed structure of the plasma sheath a...
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Article
Physisorption kinetics of electrons at plasma boundaries
Plasma-boundaries floating in an ionized gas are usually negatively charged. They accumulate electrons more efficiently than ions leading to the formation of a quasi-stationary electron film at the boundaries....
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Chapter
Quantum Percolation in Disordered Structures
Many solids, such as alloys or doped semiconductors, form crystals consisting of two or more chemical species. In contrast to amorphous systems, they show a regular, periodic arrangement of sites but the diffe...
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Book
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Article
Exact numerical methods for electron-phonon problems
In the last few years solid state physics has increasingly benefited from scientific computing and the significance of numerical techniques is likely to keep on growing quickly in this field. Because of the hi...
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Chapter
Numerical Solution of the Holstein Polaron Problem
Noninteracting itinerant electrons in a solid occupy Bloch one-electron states. Phonons are collective vibrational excitations of the crystal lattice. The basic electron-phonon (EP) interaction process is the ...
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Article
Local distribution approach to disordered binary alloys
We study the electronic structure of the binary alloy and (quantum) percolation model. Our study is based on a self-consistent scheme for the distribution of local Green functions. We obtain detailed results ...
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Article
Nature of the Peierls- to Mott-insulator transition in 1D
In order to clarify the physics of the crossover from a Peierls band insulator to a correlated Mott-Hubbard insulator, we analyze ground-state and spectral properties of the one-dimensional half-filled Holstei...
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Article
Interplay of charge, spin, orbital and lattice correlations in colossal magnetoresistance manganites
We derive a realistic microscopic model for doped colossal magnetoresistance manganites, which includes the dynamics of charge, spin, orbital and lattice degrees of freedom on a quantum mechanical level. The m...
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Chapter and Conference Paper
Jacobi-Davidson Algorithm with Fast Matrix-Vector Multiplikation on Massively Parallel and Vector Supercomputers
The exact diagonalization of very large sparse matrices is a numerical problem common to various fields in science and engineering. We present an advanced eigenvalue alorithm - the so-called Jacobi-Davidson al...
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Article
Pairing Susceptibility of Strongly Correlated Electrons Weakly Coupled to the Lattice
We analyze numerical exact results for the d-wave pairingcorrelations in the two-dimensional Holstein tJ model in terms of aneffective independent boson approach.
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Article
A new model to describe the physics of
In the past different models for the magnetic salt vanadyl pyrophosphate (VO)2P2O7 were discussed. Neither a spin ladder nor an alternating chain are capable to describe recently measured magnetic excitations. In...
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Article
Spectral properties of the 2D Holstein polaron
The two-dimensional Holstein model is studied by means of direct Lanczos diagonalization preserving the full dynamics and quantum nature of phonons. We present numerical exact results for the single-particle s...
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Article
Theory of short-range magnetic order for the t-J model
We present a self-consistent theory of magnetic short-range order based on a spin-rotation-invariant slaveboson representation of the 2D t-J model. In the functional-integral scheme, at the nearest-neighbour p...
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Article
Interplay of charge and spin correlations in nickel perovskites
Analyzing the motion of low-spin (s=1/2) holes in a high-spin (S=1) background, we derive a sort of generalized t-J Hamiltonian for the NiO2 planes of Sr-doped nickelates. In addition to the rather complex carrie...
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Article
Electron correlations and quantum lattice vibrations in strongly coupled electron-phonon systems: A variational slave boson approach
We investigate the ground-state properties of the two-dimensional Hubbard model with an additional Holstein-type electron-phonon coupling on a square lattice. The effects of quantum lattice vibrations on the s...
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Article
Dynamic spin and charge susceptibilities in thet−J model
Based on the spin-rotation-invariant formulation of the Kotliar Ruckenstein slave-boson representation, the paramagnetic spin and charge susceptibilities in thet-J model are calculated. Analyzing the static spin ...
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Article
Polaron formation and hop** conductivity in the Holstein-Hubbard model
On the basis of the Holstein-Hubbard model the formation of polarons at finite densities is investigated by means of a variational approach appropriate for describing squeezing and correlation effects. An effe...
