Related papers: Hydroxyl vacancies in single-walled aluminosilicat…
In this study, oxygen vacancies and adatoms have been considered on the surface of both hexagonal and triangular ZnO nanowires. Their effect on the electronic structure and optical spectra of the nanowires have been investigated using the…
Based on first-principles calculations we showed that superlattices of periodically repeated junctions of hydrogen saturated silicon nanowire segments having different lengths and diameters form multiple quantum well structures. The band…
All materials have defects and many contain nanostructures, both of which disrupt chemical bonding - the basis of materials properties. No experimental measurements of bonding electron distributions associated with defects and…
First principles calculations based on hybrid density functional theory have been used to study the electronic and geometric properties of armchair silicon and germanium nanotubes ranging from A (3, 3) through A (9, 9). The approach used is…
The electronic structure of a cubic $\mathcal{T}$-symmetric Weyl semimetal is analysed in the presence of atomic-sized vacancy defects. Isolated vacancies are shown to generate nodal bound states with $r^{{\scriptscriptstyle -2}}$…
We study the effects of nanoscale impurity structures on the local electronic structure of $d_{x^2-y^2}$-wave superconductors. We show that the interplay between the momentum dependence of the superconducting gap, the geometry of the…
In this work, we have examined how the multi-vacancy defects induced in the horizontal direction change the energetics and the electronic structure of semiconducting Single-Walled Carbon Nanotubes (SWCNTs). The electronic structure of…
The gap oscillations caused by a magnetic flux penetrating a carbon nanotube represent one of the most spectacular observation of the Aharonov-Bohm effect at the nano--scale. Our understanding of this effect is, however, based on the…
We report first-principles calculations which demonstrate that vacancies can combine with hydrogen impurities in bulk aluminum and play a crucial role in the embrittlement of this prototypical ductile solid. Our studies of hydrogen-induced…
Density functional methods have been used to calculate the electronic properties of aligned smalldiameter single-walled carbon nanotubes under hydrostatic pressures. Abrupt pressure induced semiconductor-metal and metal-semiconductor…
We show, using ab initio total energy density functional theory, that the so-called Wigner defects, an interstitial carbon atom right besides a vacancy, which are present in irradiated graphite can also exist in bundles of carbon nanotubes.…
We discuss a new type of topological defect in XY systems where the O(2) symmetry is broken in the presence of a boundary. Of particular interest is the appearance of such defects in nanomagnets with a planar geometry. They are manifested…
We study the binding energy, intertube distance and electronic structure of bundles consisting of single walled carbon nanotubes of the same chirality. We model various nanotube structures (chiralities) and orientations with van der Waals…
Primary metallic, or small gap semiconducting nanotubes, are tubes with band gaps that arise solely from breaking the bond symmetry due to the curvature. We derive an analytic expression for these gaps by considering how a general symmetry…
We present a first-principles study of bare and hydrogen passivated armchair nanoribbons of the puckered single layer honeycomb structures of silicon and germanium. Our study includes optimization of atomic structure, stability analysis…
In this work we report new silicon and germanium tubular nanostructures with no corresponding stable carbon analogues. The electronic and mechanical properties of these new tubes were investigated through ab initio methods. Our results show…
Recent experiments on hydrogenated amorphous silicon using infrared absorption spectroscopy have indicated the presence of mono- and divacancy in samples for concentration of up to 14\% hydrogen. Motivated by this observation, we study the…
The band structure and size-scaling of electronic properties in self-assembled cyclic oligothiophene nanotubes are investigated using density functional theory (DFT) for the first time. In these unique tubular aggregates, the {\pi}-{\pi}…
We theoretically study the interplay between electrical and mechanical properties of suspended, doubly clamped carbon nanotubes in which charging effects dominate. In this geometry, the capacitance between the nanotube and the gate(s)…
We show that the electronic and atomic structure of carbon nanotubes undergo dramatic changes with hydrogen chemisorption from first principle calculations. Upon uniform exohydrogenation at half coverage, the cross sections of zigzag…