Hülsen, Björn, Kratzer, Peter, Scheffler, Matthias
Previous studies indicated that intrinsic point defects play a crucial role for the density of states of ferromagnetic half-metals in the band gap region: At large concentrations, defect-derived...
Adsorption of Indium on a InAs wetting layer deposited on the GaAs(001) surface (2008)
Rosini, Marcello, Magri, Rita, Kratzer, Peter
In this work we perform a first-principles study of the adsorption properties of an In adatom deposited on 1.75 monolayers (ML) InAs, forming a wetting layer on GaAs$(001)$ with the $\alpha_2...
Hammerschmidt, Thomas, Kratzer, Peter, Scheffler, Matthias
A parametrization of the Abell–Tersoff potential for In, Ga, As, InAs, and GaAs is presented by using both experimental data and results from density-functional calculations as input. This...
Buecking, Norbert, Kratzer, Peter, Scheffler, Matthias, Knorr, Andreas
We describe an approach that links the density-matrix theory for electron transport and relaxation with the density-functional theory for electronic structure. Our analysis of the electron dynamics...
Buecking, Norbert, Butscher, S., Richter, M., Weber, C., Declair, S., Woerner, M., ...
A theory of electron relaxation for electron gases in semiconductor quantum well structures and at semiconductor surfaces is presented. The electron relaxation is described by quantum-kinetic...
Hortamani, Mahboubeh, Sandratskii, Leonid, Kratzer, Peter, Mertig, Ingrid, Scheffler, Matthias
Recent theoretical work [H. Wu et al., Phys. Rev. Lett. 92, 237202 (2004); M. Hortamani et al., Phys. Rev. B 74, 205305 (2006); M. Hortamani, Ph.D. thesis, Freie Universität, Berlin, 2006] predicted...
Richter, Marten, Butscher, Stefan, Bücking, Norbert, Milde, Frank, Weber, Carsten, Kratzer, Peter, ...
Bisson, Régis, Philippe, Laurent, Châtelet, Marc, Kratzer, Peter
In their article, Inanaga et al. have presented an angular distribution for the desorption of hydrogen molecules induced by hydrogen atoms impinging on a hydrogenated Si(100) surface and compared the...
Density-functional theory study of half-metallic heterostructures: interstitial Mn in Si (2007)
Wu, Hua, Kratzer, Peter, Scheffler, Matthias
Using density-functional theory within the generalized gradient approximation, we show that Si-based heterostructures with 1/4 layer $\delta$-doping of {\em interstitial} Mn (Mn$_{\mathrm int}$) are...
Buecking, Norbert, Scheffler, Matthias, Kratzer, Peter, Knorr, Andreas
A theory for the description of optical excitation and the subsequent phonon-induced relaxation dynamics of nonequilibrium electrons at semiconductor surfaces is presented. In the first part, the...
Density-functional theory study of half-metallic heterostructures: Interstitial Mn in Si (2007)
Wu, Hua, Kratzer, Peter, Scheffler, Matthias
Using density-functional theory within the generalized gradient approximation, we show that Si-based heterostructures with 1/4 layer δ doping of interstitial Mn (Mnint) are half-metallic. For Mnint...
Transition-metal silicides as materials for magnet-semiconductor heterostructures (2007)
Kratzer, Peter, Hashemifar, S. Javad, Wu, Hua, Hortamani, Mahbube, Scheffler, Matthias
The injection of a spin-polarized current into a semiconductor, one of the key requirements for spintronics, poses the challenge for computational materials science to possibly screen suitable...
Hammerschmidt, Thomas, Kratzer, Peter, Scheffler, Matthias
The elastic energy of a biaxially strained material depends on both the magnitude and the plane of the applied biaxial strain, and the elastic properties of the material. We employ...
Diffusion pathways of hydrogen across the steps of a vicinal Si(001) surface (2007)
Lawrenz, M., Kratzer, Peter, Schwalb, C. H., Dürr, M., Höfer, U.
Hydrogen diffusion across DB steps on Si(001) surfaces is investigated by means of variable-temperature scanning tunneling microscopy and first-principles calculations. Experimentally, the hopping...
Electronic structure changes of Si(001)-(2x1) from subsurface Mn observed by STM (2007)
Krause, M. R., Stollenwerk, A. J., Reed, J., LaBella, V. P., Hortamani, Mahbube, Kratzer, Peter, ...
The deposition of Mn atoms onto the Si(001)-(2x1) reconstructed surface has been studied using scanning tunneling microscopy (STM) and first-principles electronic structure calculations....
Strain field calculations of quantum dots - a comparison study of two methods (2007)
Kunert, R., Schöll, E., Hammerschmidt, Thomas, Kratzer, Peter
Santoprete, R., Kratzer, Peter, Scheffler, Matthias, Capaz, Rodrigo B., Koiller, Belita
We present an atomistic study of the strain field, the one-particle electronic spectrum and the oscillator strength of the fundamental optical transition in chemically disordered InxGa1−xAs...
Hortamani, Mahbube, Kratzer, Peter, Scheffler, Matthias
The stability of thin films and of small crystallites of Mn monosilicide (MnSi) on the Si(111) surface is investigated by density-functional theory calculations. Extending previous studies of...
Development of XFA based Electronic Workflows for the Fachhochschule Regensburg (2006)
Diese Diplomarbeit evaluiert die Features der PDF-Version 1.6 hinsichtlich elektronischer Workflows. Zu diesem Zweck wurden XFA-basierte Workflows erstellt für Reiseanträge und Reiseabrechnungen....
Kratzer, Peter, Liu, Q. K. K., Acosta-Diaz, P., Manzano, C., Costantini, G., Songmuang, R., ...
For heteroepitaxial growth of InAs islands on GaAs(001), a transition of shapes is observed experimentally by scanning-tunneling microscopy and analyzed theoretically in terms of the thermodynamic...
Takahasi, M., Kratzer, Peter, Penev, Evgeni, Mizuki, J.
The surface structure of GaAs(0 0 1)-c(4 x 4) was investigated by synchrotron surface X-ray diffraction which is sensitive to both inplane and out-of-plane structures. The atomic coordinates and...
Chakrabarti, Aparna, Kratzer, Peter, Scheffler, Matthias
Density-functional theory calculations were carried out for various surface reconstructions of atomically ordered thin films of InxGa1−xAs on the InP(001) substrate for compositions close to x=1/2....
Seguin, Robert, Schliwa, Andrei, Germann, T. D., Rodt, S., Pötschke, K., Strittmatter, A., ...
A systematic study of the impact of annealing on the electronic properties of single InAs/GaAs quantum dots (QDs) is presented. Single QD cathodoluminescence spectra are recorded to trace the...
Hortamani, Mahbube, Wu, Hua, Kratzer, Peter, Scheffler, Matthias
Ultrathin films of manganese silicides on silicon are of relevance as a possible material system for building spintronics devices with silicon technology. In order to achieve insight into epitaxial...
Au wetting and nanoparticle stability on GaAs(111)B (2006)
Hilner, E., Mikkelsen, A., Eriksson, J., Andersen, J. N., Lundgren, E., Zakharov, A., ...
Au nanoparticles and Au films for growth of nanowires on the GaAs(111)B surface have been studied by a combination of experimental and theoretical techniques. If Au is present in either form,...
First-principles study of thin magnetic transition-metal silicide films on Si(001) (2005)
Wu, Hua, Kratzer, Peter, Scheffler, Matthias
In order to combine silicon technology with the functionality of magnetic systems, a number of ferromagnetic (FM) materials have been suggested for the fabrication of metal/semiconductor...
Structure and morphology of the As-rich and the stoichiometric GaAs(114)A surface (2004)
Márquez,Juan, Kratzer,Peter, Jacobi,Karl
GaAs(114)A surfaces were prepared using molecular beam epitaxy followed by annealing in As-2 pressure as well as in ultrahigh vacuum. Based on low-energy electron diffraction, in situ scanning...
First-principles study of ferromagnetism in epitaxial Si-Mn thin films on Si(001) (2004)
Wu,Hua, Hortamani,Mahbube, Kratzer,Peter, Scheffler,Matthias
First-principles study of ferromagnetism in epitaxial Si-Mn thin films on Si(001) (2004)
Wu, Hua, Hortamani, Mahbube, Kratzer, Peter, Scheffler, Matthias
Structure and morphology of the As-rich and the stoichiometric GaAs(114)A surface (2004)
Márquez, Juan, Kratzer, Peter, Jacobi, Karl
GaAs(114)A surfaces were prepared using molecular beam epitaxy followed by annealing in As-2 pressure as well as in ultrahigh vacuum. Based on low-energy electron diffraction, in situ scanning...
Santoprete, Roberto, Koiller, Belita, Capaz, R. B., Kratzer, Peter, Liu, Q. K. K., Scheffler, Matthias
InAs quantum dots grown on the GaAs(113)A and GaAs(-1-1-3)B surfaces: A comparative STM study (2003)
Temko, Yevgeniy, Suzuki, Takayuki, Kratzer, Peter, Jacobi, Karl
InAs quantum dots (QD's) were grown on GaAs(113)A and GaAs((1) over bar(1) over bar(3) over bar )B substrates by molecular-beam epitaxy. Atomically resolved scanning tunneling microscopy images...
Surface structure of GaAs(2 5 11) (2002)
Geelhaar,Lutz, Temko,Yevgeniy, Márquez,Juan, Kratzer,Peter, Jacobi,Karl
GaAs samples with orientations vicinal to (2 5 11) within 1degree were prepared by molecular beam epitaxy and analyzed in situ by scanning tunneling microscopy, low-energy electron diffraction, and...
Quantum Monte Carlo calculations of H2 dissociation on Si(001) (2002)
Filippi,Claudia, Healy,Sorcha B., Kratzer,Peter, Pehlke,Eckhard, Scheffler,Matthias
Surface structure of GaAs(2 5 11) (2002)
Geelhaar,Lutz, Temko,Yevgeniy, Márquez,Juan, Kratzer,Peter, Jacobi,Karl
Quantum Monte Carlo calculations of H2 dissociation on Si(001) (2002)
Filippi, Claudia, Healy, Sorcha B., Kratzer, Peter, Pehlke, Eckhard, Scheffler, Matthias
Surface structure of GaAs(2 5 11) (2002)
Geelhaar, Lutz, Temko, Yevgeniy, Márquez, Juan, Kratzer, Peter, Jacobi, Karl
Surface structure of GaAs(2 5 11) (2002)
Geelhaar, Lutz, Temko, Yevgeniy, Márquez, Juan, Kratzer, Peter, Jacobi, Karl
GaAs samples with orientations vicinal to (2 5 11) within 1degree were prepared by molecular beam epitaxy and analyzed in situ by scanning tunneling microscopy, low-energy electron diffraction, and...
Effect of strain on surface diffusion in semiconductor heteroepitaxy (2001)
Penev, Evgeni, Kratzer, Peter, Scheffler, Matthias
We present a first-principles analysis of the strain renormalization of the cation diffusivity on the GaAs(001) surface. For the example of In/GaAs(001)-c(4x4) it is shown that the binding of In is...
Probing interface electronic structure with overlayer quantum-well resonances: Al/Si(111) (2001)
Aballe,L., Rogero,Celia, Kratzer,Peter, Gokhale,S., Horn,Karsten
The role of electronic correlation in the Si(100) reconstruction: a quantum Monte Carlo study (2001)
Healy,S. B., Filippi,C., Kratzer,Peter, Penev,Evgeni, Scheffler,Matthias
Atomic structure of the stoichiometric GaAs(114) surface (2001)
J. Márquez,J., Kratzer,Peter, Geelhaar,Lutz, Jacobi,Karl, Scheffler,Matthias
Probing interface electronic structure with overlayer quantum-well resonances: Al/Si(111) (2001)
Aballe, L., Rogero, Celia, Kratzer, Peter, Gokhale, S., Horn, Karsten
The role of electronic correlation in the Si(100) reconstruction: a quantum Monte Carlo study (2001)
Healy, S. B., Filippi, C., Kratzer, Peter, Penev, Evgeni, Scheffler, Matthias
Island dissolution during capping layer growth interruption (2001)
Wang, L. G., Kratzer, Peter, Scheffler, Matthias, Liu, Q. K. K.
Atomic structure of the stoichiometric GaAs(114) surface (2001)
J. Márquez, J., Kratzer, Peter, Geelhaar, Lutz, Jacobi, Karl, Scheffler, Matthias
GaAs(2 5 11) – A new stable surface within the stereographic triangle (2001)
Geelhaar, Lutz, Márquez, Juan, Kratzer, Peter, Jacobi, Karl
The atomic structure of GaAs(2 5 11), a hitherto unknown stable surface, has been determined by in situ scanning tunneling microscopy and first-principles electronic structure calculations. This...