相关论文: Analysis of characteristics of Al MKID resonators
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 study the response of several microwave resonators made from superconducting NbTiN thin-film meandering nanowires with large kinetic inductance, having different circuit topology and coupling to the transmission line. Reflection…
Aluminosilicate (Al-Si-O) thin films containing up to 31 at. % Al and 23 at. % Si were prepared by reactive RF magnetron co-sputtering. Mechanical and structural properties were measured by indentation and specular reflectance infrared…
The overall, loaded quality factor $Q_\mathrm{L}$ quantifies the loss of energy stored in a resonator. Here we discuss on general grounds how $Q_\mathrm{L}$ of a planar microwave resonator made of a conventional superconductor should depend…
The performance of superconducting resonators underpins a wide range of modern quantum technologies, yet their quality factor often deviates at low temperatures from standard Mattis-Bardeen predictions. This discrepancy is often attributed…
We report the reduction in residual stress of AlN thin films and also the crystal structure, surface morphology and nanomechanical properties of magnetron sputtered as a function of substrate temperature (Ts, 35 - 600 ?C). The residual…
We systematically study the performance of compact lumped element planar microwave $\mathrm{Nb_{70}Ti_{30}N}$ (NbTiN) resonators operating at 5 GHz in external in-plane magnetic fields up to 440 mT, a broad temperature regime from 2.2 K up…
Superconducting thin films with high intrinsic kinetic inductance $L_{k}$ are important for high-sensitivity detectors, enabling strong coupling in hybrid quantum systems, and enhancing nonlinearities in quantum devices. We report the…
By studying the temperature-dependent behavior of electron thermal conductivity (k) in a 3.2 nm-thin film, we quantify the extremely confined defect-electron scattering and reveal the intrinsic phonon-electron scattering that is shared by…
We investigate the performance of microwave-frequency phononic crystal resonators fabricated on thin-film lithium niobate for integration with superconducting quantum circuits. For different design geometries at millikelvin temperatures, we…
The high critical magnetic field and relatively high critical temperature of niobium nitride (NbN) make it a promising material candidate for applications in superconducting quantum technology. However, NbN-based devices and circuits are…
We report on magnetoconductance measurements through a weakly coupled quantum dot, containing roughly 900 electrons, in a wide magnetic field range from 0 T to 12 T. We find modulations of the conductance resonances in the quantum Hall…
Scalable architectures characterized by quantum bits (qubits) with low error rates are essential to the development of a practical quantum computer. In the superconducting quantum computing implementation, understanding and minimizing…
Superconducting microwave resonators have recently gained a primary importance in the development of cryogenic applications, such as circuit quantum electrodynamics, electron spin resonance spectroscopy and particles detection for…
We report on the study of phonon properties and electron-phonon coupling in thin NbTiN films, which are intensively exploited in superconducting devices. Studied NbTiN films with thicknesses less than 10~nm are disordered with respect to…
The performance of superconducting microwave circuits is strongly influenced by the material properties of the superconducting film and substrate. While progress has been made in understanding the importance of surface preparation and the…
We have designed, fabricated and characterized microwave resonators made out of thin films of granular aluminium (grAl) with different oxygen content. We extract the contribution of the large kinetic-inductance of this disordered…
A15 superconductors are distinguished by their high critical temperatures, magnetic fields, and current-carrying capabilities. Among them, Nb$_3$Al is of particular interest for superconducting quantum circuits as a means to extend device…
Sputtered Nb thin-film LC resonators for low frequencies at 0.5 MHz have been fabricated and tested in the temperature range 0.05--1 K in magnetic fields up to 30 mT. Their Q value increases towards decreasing temperature as sqrt(T) and…
We report data on the thermal conductivity K(T,H) along the basal plane of the hexagonal crystal structure of superconducting Mg{1-y}Al{y}B2 with y=0.02 and 0.07 at temperatures between 0.5 and 50 K and in external magnetic fields between 0…