Related papers: Microwave transmissions through superconducting co…
The discovery of van der Waals superconductors in recent years has generated a lot of excitement for their potentially novel pairing mechanisms. However, their typical atomic-scale thickness and micrometer-scale lateral dimensions impose…
Coupling carbon nanotube devices to microwave circuits offers a significant increase in bandwidth and signal-to-noise ratio. These facilitate fast non-invasive readouts important for quantum information processing, shot noise and…
Superconducting metamaterials are a promising resource for quantum information science. In the context of circuit QED, they provide a means to engineer on-chip, novel dispersion relations and a band structure that could ultimately be…
We describe progress and initial results achieved towards the goal of developing integrated multi-conductor arrays of shielded controlled-impedance flexible superconducting transmission lines with ultra-miniature cross sections and wide…
We have developed and tested a doubly tunable resonator, with the intention to simulate fast motion of the resonator boundaries in real space. Our device is a superconducting coplanar-waveguide half-wavelength microwave resonator, with…
Surface acoustic waves (SAWs), with their five orders-of-magnitude slower propagation velocity, allow for considerably shorter wavelengths at the same frequency compared to electromagnetic waves. The short wavelengths allow for device…
We have performed susceptibility, thermopower, dc resistance and microwave measurements on RuSr2EuCu2O8. This compound has recently been shown to display the coexistence of both superconducting and magnetic order. We find clear evidence of…
We report microwave impedance measurements of a superconductor-semiconductor hybrid nanowire device with three terminals (3T). Our technique makes use of transmission line resonators to acquire the nine complex scattering matrix parameters…
We demonstrate how heating of an environment can invert the line shape of a driven cavity. We consider a superconducting coplanar cavity coupled to multiple artificial atoms. The measured cavity transmission is characterized by Fano-type…
We present low-temperature measurements of low-loss superconducting nanowire-embedded resonators in the low-power limit relevant for quantum circuits. The superconducting resonators are embedded with superconducting nanowires with widths…
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…
This work studies high-temperature superconducting spiral resonators as a viable candidate for realization of RF/microwave metamaterial atoms. The theory of superconducting spiral resonators will be discussed in detail, including the…
We report the measurement of the acoustic quality factor of a gram-scale, kilo-hertz frequency superfluid resonator, detected through the parametric coupling to a superconducting niobium microwave cavity. For temperature between 400mK and…
We demonstrate impedance-matched low-loss transmission lines with a signal wavelength more than 150 times smaller than the free space wavelength using superconducting nanowires on high permittivity substrates. A niobium nitride thin film is…
The fragile nature of quantum circuits is a major bottleneck to scalable quantum applications. Operating at cryogenic temperatures, quantum circuits are highly vulnerable to amplifier backaction and external noise. Non-reciprocal microwave…
We present a high-resolution microwave spectrometer to measure the frequency-dependent complex conductivity of a superconducting thin film near the critical temperature. The instrument is based on a broadband measurement of the complex…
Surface impedance measurements of LuNi2B2C superconducting thin films as a function of temperature have been performed down to 1.5 K and at 20 GHz using a dielectric resonator technique. The magnetic penetration depth closely reproduces the…
MgB2 superconducting wires with critical temperature Tc approaching 40 K were used for preparation of MgB2/Ag and MgB2/In junctions. The differential conductance vs. voltage characteristics of N-S junctions exhibit clear contribution of…
Our objective is to study the extreme and local electrodynamic properties of Niobium (Nb), and to relate these properties to specific defects that limit the ultimate RF performance of superconducting radio frequency (SRF) cavities made from…
We study superconductor-ferromagnet bi-layers, not only for s-wave but also for d-wave superconductors. We observe oscillations of the critical temperature when varying the thickness of the ferromagnetic layer for both s-wave and d-wave…