Related papers: RF surface resistance tuning of superconducting ni…
Niobium and its alloys with early transition metals have been extensively studied for their excellent superconducting properties. They have high transition temperatures, strong upper critical fields, and high critical current densities,…
The surface resistance of an RF superconductor depends on the surface temperature, the residual resistance and various superconductor parameters, e.g. the energy gap, and the electron mean free path. These parameters can be determined by…
In this work we investigate superconducting properties of niobium samples via application of the muon spin rotation/relaxation (muSR) technique. We employ for the first time the muSR technique to study samples that are cutout from large and…
Topographic structure on Superconductivity Radio Frequency (SRF) surfaces can contribute additional cavity RF losses describable in terms of surface RF reflectivity and absorption indices of wave scattering theory. At isotropic homogeneous…
Even when cooled through its transition temperature in the presence of an external magnetic field, a superconductor can expel nearly all external magnetic flux. This Letter presents an experimental study to identify the parameters that most…
Previous work has demonstrated that the radio frequency surface resistance of niobium resonators is dramatically reduced when nitrogen impurities are dissolved as interstitial in the material. The origin of this effect is attributed to the…
This contribution discusses the results of an in-situ angular XPS study on the thermal evolution of the native oxide layer on Nb3Sn and pure Nb. XPS data were recorded with conventional spectrometers using an AlK(alpha) X-ray source for…
Niobium films are of interest in applications in various superconducting devices, such as superconducting radiofrequency cavities for particle accelerators and superconducting qubits for quantum computing. In this study, we addressed the…
Niobium is one of the most studied superconductors, both theoretically and experimentally. It is tremendously important for applications, and it has the highest superconducting transition temperature, $T_{c}=9.33$ K, of all pure metals. In…
Nanoscale defect structure within the magnetic penetration depth of ~100nm is key to the performance limitations of niobium superconducting radio frequency (SRF) cavities. Using a unique combination of advanced thermometry during cavity RF…
The performance of superconducting radio-frequency (SRF) cavities made of Niobium is tied to the quality of their inner surfaces exposed to the radio frequency (RF) waves. Future superconducting particle accelerators, because of their…
We have developped a novel lift-off process for fabrication of high quality superconducting submicron niobium structures. The process makes use of a thermostable polymer with a high transition temperature T_{g}= 235 C and an excellent…
Near-field (NF) radiative heat transfer (RHT) over vacuum space between closely spaced bodies can exceed the Planck far-field (FF) values by orders of magnitude. Strong effect of superconductivity on NF RHT between plane-parallel thin-film…
Scalable quantum computing currently requires a large array of qubit integration, but present two-dimensional interconnects face challenges such as wiring congestion, electromagnetic interference, and limited cryogenic space. To overcome…
We applied heat treatments to 80.5 MHz quarter-wave resonators made from bulk niobium and prepared with buffered chemical polishing BCP. We evaluated their performance at 4.3 K. We found that a 48 hour, 120 C bake-out ("low-temperature bake…
We determine the thermal conductance of thin niobium (Nb) wires on a silica substrate in the temperature range of 0.1 - 0.6 K using electron thermometry based on normal metal-insulator-superconductor tunnel junctions. We find that at 0.6 K,…
The electrical resistivity of conventional metals, such as copper, is known to increase in thin films due to electron-surface scattering, limiting the performance of metals in nanoscale electronics. Here, we find an unusual reduction of…
Identifying the loss mechanisms of niobium cavities enables an accurate determination of applications for future accelerator projects and points to research topics required to mitigate current limitations. For several cavities an increasing…
Since the late '80s, CERN has pioneered the development of niobium thin film radio-frequency (RF) cavities deposited on copper substrates for several particle accelerator applications. However, niobium thin film cavities historically…
Superconducting niobium serves as a key enabling material for superconducting radio frequency (SRF) technology as well as quantum computing devices. At room temperature, hydrogen commonly occupies tetragonal sites in the Nb lattice as metal…