Related papers: Schwoebel barriers on Si(111) steps and kinks
It is shown that the topological discrete sine-Gordon system introduced by Speight and Ward models the dynamics of an infinite uniform chain of electric dipoles constrained to rotate in a plane containing the chain. Such a chain admits a…
We present an entirely analytic, leading log order determination of the friction an electroweak bubble wall feels during a first order electroweak phase transition. The friction is dominated by W bosons, and gives a wall velocity…
Cobalt silicide (CoSi2) islands have been formed by the deposition of thin films (~0.1 to 0.3 nm) of cobalt on clean Si(111) and Si(100) substrates in ultrahigh vacuum (UHV) followed by annealing to ~880 degrees C. Conducting atomic force…
We have used Low Energy Electron Diffraction (LEED) I-V analysis and ab initio calculations to quantitatively determine the honeycomb chain model structure for the Si(111)-3x2-Sm surface. This structure and a similar 3x1 recontruction have…
Based on scanning tunneling microscopy and first-principles theoretical studies, we characterize the precise atomic structure of a topological soliton in In chains grown on Si(111) surfaces. Variable-temperature measurements of the soliton…
Thin Ge layers deposited on Si(105) form a stable single-domain film structure with large terraces and rebonded-step surface termination, thus realizing an extended and ordered Ge/Si planar hetero-junction. At the coverage of four Ge…
An alternate formalism is developed to determine the energy eigenvalues of quantum mechanical systems, confined within a rigid impenetrable spherical box of radius $r_0$, in the framework of Wentzel-Kramers-Brillouin (WKB) approximation.…
We propose and demonstrate a relaxed-SiGe/strained-Si (SiGe/s-Si) enhancement-mode gate stack for quantum dots. The enhancement-mode SiGe/s-Si structure is pursued because it spaces the quantum dot away from charge and spin defect rich…
This thesis presents an extensive analysis of the behavior of topological solitons when one or more of their internal modes are activated. The first part of this manuscript is devoted to the study of the simplest topological solitons in…
When examining dynamics occurring at non-zero temperatures, both energy and entropy must be taken into account while describing activated barrier crossing events. Furthermore, good reaction coordinates need to be constructed to describe…
We conisder the brittle versus ductile behavior of aluminum in the framework of the Peierls-model analysis of dislocation emission from a crack tip. To this end, we perform first-principles quantum mechanical calculations for the unstable…
The stopping cross sections S (E) of silicon for protons and alpha particles have been measured over the velocity range 0.3-1.2 MeV/u from a SIMOX target using the Rutherford Backscattering Spectrometry (RBS) with special emphasis put on…
Kinks, point-like geometrical defects along dislocations, domain walls, and DNA, are stable and mobile, as solutions of a sine-Gordon wave equation. While they are widely investigated for crystal deformations and domain wall motions,…
We report for the first time the observation of bunching of monoatomic steps on vicinal W(110) surfaces induced by step up or step down currents across the steps. Measurements reveal that the size scaling exponent {\gamma}, connecting the…
We theoretically investigate the spin structure of weakly bound diatomic van der Waals molecules formed by two identical bosonic alkali atoms. Our studies were performed using known Born-Oppenheimer potentials while developing a reduced…
Using total energy calculations, based on interaction potentials from the embedded atom method, we show that the presence of the tip not only lowers the barrier for lateral diffusion of the adatom towards it, but also shifts the…
We report on calculations of the formation energies of several [100] and [110] oriented step structures on biaxially stressed Si and Ge (001) surfaces. It is shown that a novel rebonded [100] oriented single-height step is strongly…
The $B$(E1;$1/2^+\to1/2^-$) strength for $^{11}$Be has been extracted from intermediate energy Coulomb excitation measurements, over a range of beam energies using a new reaction model, the extended continuum discretized coupled channels…
Si(111) and Ge(111) surface formation energies were calculated using density functional theory for various biaxial strain states ranging from -0.04 to 0.04, and for a wide set of experimentally observed surface reconstructions: 3x3, 5x5,…
We use the two loop effective potential to study the first order electroweak phase transition in the minimial supersymmetric standard model. A global search of the parameter space is made to identify parameters compatible with electroweak…