Related papers: $\textit{Ab Initio}$ Study of Antisite Defects in …
We extend the Ginzburg-Landau-Abrikosov-Gor'kov (GLAG) theory to account for the variation of the upper critical field Hc2 with Sn content in A15-type Nb3Sn. Hc2 at the vicinity of the critical temperature Tc is related quantitatively to…
Bulk niobium is the material mostly used in RF superconducting cavities for accelerator. Predicting and reducing the surface dissipation in RF is mandatory, since it has a tremendous cost impact on most of the large accelerator projects.…
Nowadays Nb-based superconducting radio-frequency cavities represent fundamental tools used for (Standard Model) particle acceleration, (beyond Standard Model) particle probing, and long-lifetime photon preservation. We study the SRF…
We report on a combined scanning tunneling microscopy and density functional theory calculation study of the SrTiO3(110)-(4 x 1) surface. It is found that antiphase domains are formed along the [1-10]-oriented stripes on the surface. The…
We report on a Nb$_3$Sn-coated low-beta superconducting radio frequency (SRF) cavity intended for accelerating ions. We aim to apply the cavity in ATLAS, our Argonne National Laboratory user facility for nuclear physics studies with ion…
The functionalization of semiconducting single-wall carbon nanotubes (SWCNTs) with luminescent sp$^{3}$ defects creates red-shifted emission features in the near-infrared and boosts their photoluminescence quantum yields (PLQYs). While…
The fine control of magnetism and electronic structure is crucial since the interplay between magnetism and band topology can lead to various novel magnetic topological states including axion insulators, magnetic Weyl semimetals and Chern…
The presence of defects in the narrow-gap semiconductors GaSb and InSb affects their dopability and hence applicability for a range of optoelectronic applications. Here, we report hybrid density functional theory based calculations of the…
We present an analysis of the Nb3Sn surface layers grown on a bulk niobium (Nb) coupon prepared at the same time and by the same vapor diffusion process used to make Nb3Sn coatings on 1.3 GHz cavities. Tunneling spectroscopy reveals a…
A simplified numerical model has been developed to simulate non-linear superconducting radiofrequency (SRF) losses on Nb surfaces. This study focuses exclusively on excessive surface resistance (Rs) losses due to the microscopic…
Nb3Sn superconducting radiofrequency (SRF) cavities have substantial potential for enabling new performance capabilities for particle accelerators for high energy physics (HEP), as well as for RF cavity-based detectors for dark matter,…
We present the first fully $ab\;initio$ microscopic description of cubic and tetragonal Nb$_3$Sn. We compute the anharmonic free energy surface, phonon spectra, and solve the full-bandwidth anisotropic Migdal-Eliashberg equations for the…
MnBi2Te4 is a versatile platform for exploring diverse topological quantum states, yet its potential is hampered by intrinsic antisite defects. While Sb substitution has been employed to tune the Fermi level towards the charge neutral…
This paper reports on a surface impedance measurement of a niobium titanium superconducting radio frequency (SRF) cavity in a magnetic field (up to $10\,{\rm T}$). A novel method is employed to decompose the surface resistance contributions…
A systematic study of the superconducting properties in a series of arc-melted Nb-B samples close to the 1:1 composition was carried out. Powder X-ray diffraction (XRD) shows that all samples are both non-stoichiometric, and comprising of…
There is a need to better understand the intrinsic limit of radiofrequency (RF) surface impedance that determines the performance of superconducting RF cavities in particle accelerators. Here we present a field-dependent derivation of…
From the magnetic response of Nb-cylinders to time-varying fields the AC-conductivity, $\sigma'-i\sigma''$, and the critical current density $J_c^s$ are determined above the upper critical field $H_{c2}$. The field dependencies of $\sigma'$…
This article gives an overview of the available literature on simplified, well defined (quasi-)homogeneous laboratory samples. After more than 50 years of research on superconductivity in Nb3Sn, a significant amount of results are…
A systematic study of crystal structure, local structure, magnetic and transport properties in quenched and temper annealed Ni$_{2-x}$Mn$_{1+x}$Sn alloys indicate the formation of Mn$_3$Sn type structural defects caused by an antisite…
The effect of a variety of intrinsic defects and defect clusters in bulk and thin films of SrTiO$_3$ on ferroelectric polarization and switching mechanism is investigated by means of density-functional-theory (DFT) based calculations and…