Browsing by Author "Çıracı, Salim"
Now showing items 21-40 of 227
-
Atomic-scale tip-sample interactions and contact phenomena
(1992)Tip-sample interactions become crucial owing to increased overlap at small tip-sample separation. The potential barrier collapses before the point of maximum attraction on the apex of the tip, but the effective barrier may ... -
An atomistic study on the stretching of nanowires
(1997)In this work we present an atomic-scale investigation of elastic and plastic deformation, and force variations in metal nanowires that are pulled from their ends. The atomic simulations are performed by using a molecular ... -
Ballistic transport through a quantum point contact: elastic scattering by impurities
(American Physical Society, 1990)The effects of elastic scattering due to impurities in a quasi-one-dimensional constriction are investigated with an exact calculation of the conductance. It is found that the quantization of conductance is distorted owing ... -
Bound-state formation on a spherical shell: A model for superconductivity of alkali-metal-doped C60
(1992)We show that an attractive interaction between two electrons confined to the surface of a sphere gives rise to a bound state, no matter how weak the interaction is. We explore the similarity between a sphere and a ... -
Calculations of STM linescans-general formalism
(Pergamon Press, 1988)We have developed a formalism for calculating the line scans of the scanning-tunneling microscopy from the realistic substrate and tip wave functions. The tip wave functions are calculated self-consistently by using a ... -
Carbon string structures: First-principles calculations of quantum conductance
(American Physical Society, 2005)Carbon forms various nanostructures based on the monatomic chains or strings which show transport properties of fundamental and technological interest. We have carried out first-principles quantum conductance calculations ... -
Chemical and substitutional doping, and anti-site and vacancy formation in monolayer AlN and GaN
(Royal Society of Chemistry, 2018)We investigated the effects of chemical/substitutional doping, hydrogenation, and anti-site and vacancy defects on the atomic, optoelectronic and magnetic properties of AlN and GaN monolayers. Upon doping of selected atoms, ... -
Chiral single-wall gold nanotubes
(American Physical Society, 2004)The formation of freestanding and tip-suspended chiral-wall (n,m) nanotubes, which were composed of helical atomic strands, from gold atoms was investigated using first-principles calculations, where (n,m) notation defines ... -
Chlorine adsorption on graphene: chlorographene
(American Chemical Society, 2012)We perform first-principles structure optimization, phonon frequency, and finite temperature molecular dynamics calculations based on density functional theory to study the interaction of chlorine atoms with graphene ... -
Columnar antiferromagnetic order of a MBene monolayer
(American Physical Society, 2021-04-16)First-principles density functional theory, combined with the Monte Carlo method, predicts that the Fe2B2 monolayer of the MBene family has a stable columnar antiferromagnetic (AFM) ground state. Below the critical ... -
A comparative study of lattice dynamics of three-and two-dimensional MoS2
(American Chemical Society, 2011)This paper presents a comparative study of the lattice dynamics of three-dimensional layered MoS2 and two-dimensional single layer MoS2 based on the density functional theory. A comprehensive analysis of energetics and ... -
A comparative study of O2 adsorbed carbon nanotubes
(2003)First-principles, density functional calculations show that O2 adsorbed single-wall carbon nanotubes (SWNT) show dramatic differences depending on the type of the tube. Upon O2 physisorption, the zig-zag SWNT remains ... -
Conductance in nanowires
(Kluwer Academic Publishers, 1997)This paper presents a detailed analysis of conductance and atomic structure in metal nanowires under tensile stress. We calculate the variation of conductance with the crossection of the constriction between two reservoirs, ... -
Conductance of ferromagnetic nanowires
(American Physical Society, 1998)The conductance distribution obtained from an ensemble of stretching ferromagnetic nanowires or point contacts do not exhibit peaks near the integer multiples of 2e2/h. This observation has been interpreted as the absence ... -
Conductance through a single atom
(American Physical Society, 1997)In this paper we present an analysis of conduction through a single atom between two metal electrodes. Based on ab initio total-energy and electronic-structure calculations, and molecular-dynamics simulations using the ... -
Conductance through atomic contacts created by scanning tunneling microscopy
(Elsevier, 1999)We investigate conductance through contacts created by pressing a hard tip, as used in scanning tunneling microscopy, against substrates. Two different substrates are considered, one a normal metal (Cu) and another a ... -
Confined states in multiple quantum well structures of Sin Gen nanowire superlattices
(American Physical Society, 2007)Mechanical properties, atomic and energy band structures of bare and hydrogen-passivated Sin Gen nanowire superlattices have been investigated by using first-principles pseudopotential plane-wave method. Undoped, tetrahedral ... -
Confinement of electrons in size-modulated silicon nanowires
(American Physical Society, 2009)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 ... -
Contact, nanoindentation, and sliding friction
(American Physical Society, 1998)This paper presents an atomic-scale study of contact, indentation, and subsequent pulling and dry sliding of a sharp and blunt metal tip on a metal surface. The evolution of atomic structure and the variation of perpendicular ... -
Controlled lateral and perpendicular motion of atoms on metal surfaces
(American Physical Society, 1996)We present the theoretical study of the controlled lateral and perpendicular motion of Xe on the Pt(111) surface. The lateral translation of Xe is manipulated by a tungsten tip of a scanning tunneling microscope. Using ...
