相关论文: Extracting superconducting parameters from surface…

Performance of superconducting resonators, particularly cavities for particle accelerators and micro cavities and thin film resonators for quantum computations and photon detectors has been improved substantially by recent materials…

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…

Particle physics and radio-frequency (RF) superconductivity have driven each other on since the 1970s. The unique properties of superconductors (SC) have been the enabling keys for the realization of accelerators with always increased…

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…

The performance of superconducting radiofrequency (SRF) cavities used for particle accelerators depends on two characteristic material parameters: field of first flux entry $H_{entry}$ and pinning strength. The former sets the limit for the…

Impurity-doping is an exciting new technology in the field of SRF, producing cavities with record-high quality factor $Q_0$ and BCS surface resistance that decreases with increasing RF field. Recent theoretical work has offered a promising…

Surface properties are critical to the capabilities of superconducting microwave devices. The native oxide of niobium-based devices is thought to consist of a thin normal conducting layer. To improve understanding on the importance of this…

The performance of superconducting radio-frequency (SRF) cavities is sometimes limited by local defects. To investigate the RF properties of these local defects, especially those that nucleate RF magnetic vortices, a near-field magnetic…

The operation of resistive and phase-change memory (RRAM and PCM) is controlled by highly localized self-heating effects, yet detailed studies of their temperature are rare due to challenges of nanoscale thermometry. Here we show that the…

Recently reported anomalies in frequency shift of order $\delta f\sim 0.1 -10\,\mbox{kHz}$ for Niobium SRF cavities in a narrow temperature region near $T_c\simeq 9\,\mbox{K}$ are sensitive to the surface preparation and Nitrogen doping. We…

Nb3Sn (Tc ~ 18 K and Hsh ~ 400 mT) is a prospective material to replace Nb (Tc ~ 9 K and Hsh ~ 200 mT) in SRF accelerator cavities for significant cost reduction and performance enhancement. Because of its material properties, Nb3Sn is best…

We have developed a low temperature, high-resolution microwave surface impedance probe that is able to operate in high static magnetic fields. Surface impedance is measured by cavity perturbation of dielectric resonators, with sufficient…

The real $R_s(T)$ and imaginary $X_s(T)$ parts of the surface impedance $Z_s(T)=R_s(T)+iX_s(T)$ in polycrystalline MgB$_2$ samples of different density with the critical temperature $T_c\approx 38$ K are measured at the frequency of 9.4 GHz…

The structure of superconducting order parameter near the surface of a two-band superconductor with $s_{\pm}$ order parameter in the bulk is theoretically investigated. The main parameter of the surface, which determines the appropriate…

Measuring the internal quality factor of coplanar waveguide superconducting resonators is an established method of determining small losses in superconducting devices. Traditionally, the resonator losses are only attributed to two-level…

We develop theoretical methods to predict the effects of paramagnetic impurities on the microwave response of conventional spin-singlet superconductors. Our focus is on superconducting devices and resonators with low concentrations of…

Superconducting-proximity topological insulators (STIs) have garnered significant research attention over the past two decades. In this Letter, we demonstrate that a low-dimensional STI in the topological-nontrivial phase (TP) exhibits an…

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…

We have created an experimental procedure for determining the temperature coefficient of resistivity, $\alpha_R$, for introductory physics laboratories. This method examines the relationship between temperature and resistivity to establish…

We present measurements and simulations of superconducting Nb co-planar waveguide resonators on sapphire substrate down to millikelvin temperature range with different readout powers. In the high temperature regime, we demonstrate that the…