相关论文: Positron lifetime calculations for defects in Zn
Theoretical positron lifetime values have been calculated systematically for most of the elements of the Periodic Table. Self-consistent and non-self-consistent schemes have been used for the calculation of the electronic structure in the…
The stability properties of vacancy clusters in hexagonal close-packed Zr, cavities and dislocation loops, are investigated at the atomic scale, with a modeling approach based on density functional theory and empirical potentials.…
Positron lifetimes have been calculated in bulk and monovacancies for most of the elements of the periodic table. Self-consistent and non-self-consistent schemes have been used for the calculation of the electronic structure in the solid,…
A model describing the relationship between the ortho--positronium lifetime and the volume of a void, located in a synthetic zeolite, is analyzed. Our idea, which allows us to take into account the effects of temperature, comprises the…
This work presents accurate {\it ab initio} determination of the magnetic dipole (M1) and electric quadrupole (E2) hyperfine structure constants for the ground and a few low-lying excited states in $^{67}$Zn$^{+}$, which is one of the…
We report a computational first-principles study of positron trapping at vacancy defects in metals and semiconductors. The main emphasis is on the energetics of the trapping process including the interplay between the positron state and the…
The results of positron annihilation lifetime spectroscopy measurements on undoped, electron irradiated, and Nb doped SrTiO3 single crystals are reported. Perfect lattice and vacancy defect positron lifetimes were calculated using two…
Electron antineutrinos are detected in organic liquid scintillator based neutrino experiments by means of the inverse beta decay, producing both a positron and a neutron. The positron may form a bound state together with an electron, called…
Understanding the nature and behavior of vacancy-like defects in epitaxial GeSn metastable alloys is crucial to elucidate the structural and optoelectronic properties of these emerging semiconductors. The formation of vacancies and their…
Neutron irradiation progressively changes the properties of zirconium alloys: they harden and their average c/a lattice parameter ratio decreases with fluence. The bombardment by neutrons produces point defects, which evolve into…
The pionium lifetime is calculated in the framework of the quasipotential-constraint theory approach, including the sizable electromagnetic corrections. The framework of generalized chiral perturbation theory allows then an analysis of the…
Some extensions of the standard model contain additional leptons which are vectorlike under weak isospin. A class of models is considered in which these leptons do not appreciably mix with the known leptons. In such models, the heavy…
Realistic calculations of nuclear disappearance lifetimes induced by neutron-antineutron oscillations are reported for oxygen and iron, using antineutron nuclear potentials derived from a recent comprehensive analysis of antiproton atomic…
Extensive irradiation of silicon crystal sensors by high energy particles in e. g. accelerators yield defect clusters of different types. Trapping of electrons and holes result in extended internal electric fields that drive remaining free…
Doped ZnO is a promising material for spintronics applications. For such applications, it is important to understand the spin dynamics and particularly the spin coherence of this II-VI semiconductor. The spin lifetime $\tau_{s}$ has been…
We calculate the lifetime of the collective isospin rotating solutions which have been found recently in the case a quantum N-component meson field with exact O(N) symmetry. For this purpose we take into account the small breaking of the…
In this paper we review the role of the neutron lifetime and discuss the present status of measurements. In view of the large discrepancy observed by the two most precise individual measurements so far we describe the different techniques…
Collective electronic excitations "excitons" in planar optical lattices exhibit strong modifications of the radiative damping rate and directional emission pattern as compared to a single excited atom. Excitons for long wave numbers and…
Oscillons are long-lived, spherically symmetric solitons that can arise in real scalar field theories with potentials shallower than quadratic ones. They are considered to form via parametric resonance during the preheating stage after…
We present a lattice calculation of neutron-deuteron scattering at very low energies and investigate in detail the impact of the topological finite-volume corrections. Our calculations are carried out in the framework of pionless effective…