Related papers: Cooling Dynamics Through Transition Temperature of…
Recently, Nb superconducting radio frequency cavities vacuum heat treated between 300-400 C for a few hours have exhibited very high quality factors (~5x10^10 at 2.0 K). New secondary ion mass spectrometry measurements of O, N and C show…
Recent discoveries of superconductivity in hydrogen-rich compounds stabilized by high pressures have shown that a critical temperature of superconductivity Tc can reach near room temperature values. The current studies focus on the search…
We study the nonlinear dynamics of an ensemble of cold trapped atoms with a hyperfine transition magnetically coupled to a resonant microwave cavity mode. Despite the minute single atom coupling one obtains strong coupling between…
Cooling microwave resonators to near the quantum ground state, crucial for their operation in the quantum regime, is typically achieved by direct device refrigeration to a few tens of millikelvin. However, in quantum experiments that…
We theoretically analyse the cooling dynamics of a high-Q mode of a mechanical resonator, when the structure is also an optical cavity and is coupled with a NV center. The NV center is driven by a laser and interacts with the cavity photon…
If phase coherence determines the superconducting transition temperature Tc in the cuprate oxides, it is of great interest to understand the role that dynamics of the phase fluctuation plays in bringing about depletion of the…
We demonstrate continuous Sisyphus cooling combined with a continuous loading mechanism used to efficiently slow down and accumulate atoms from a guided beam. While the loading itself is based on a single slowing step, applying a radio…
We report Sb-NQR results which evidence a heavy-fermion (HF) behavior and an unconventional superconducting (SC) property in the filled-skutterudite compound PrOs_4Sb_12 revealing a SC transition temperature T_c=1.85 K. The temperature (T)…
Superconductivity in organic conductors is often tuned by the application of chemical or external pressure. With this type of tuning, orbital overlaps and electronic bandwidths are manipulated, whilst the properties of the molecular…
A recently reported transition in the electrical resistance of different natural graphite samples suggests the existence of superconductivity at room temperature. To check whether dissipationless electrical currents are responsible for the…
The thermodynamic properties of the superconducting state in the amorphous ${\rm Sn_{1-x}Cu_{x}}$ thin films have been characterized. The concentration of copper changes in the range from $0.08$ to $0.41$. The calculations have been…
Recent renewal of the highest transition temperature in a conventional superconductor of the sulfer hydride attracts much attention to exploring simple compounds with the lighter elements, situated in unconventional conditions. We report…
A sudden drop in mechanical friction, between an adsorbed nitrogen monolayer and a lead substrate, occurs when the lead passes through the superconducting transition temperature. We attribute this effect to a sudden drop at the…
We report the RF performance of several single-cell superconducting radio-frequency cavities subjected to low temperature heat treatment in nitrogen environment. The cavities were treated at temperature 120 - 165 $^{\circ}$C for an extended…
Nitrogen doping study on niobium (Nb) samples used for the fabrication of the superconducting radio frequency (SRF) cavities has been carried out. The samples' surface treatment was attempted to replicate that of the SRF cavities, which…
In niobium superconducting radio frequency (SRF) accelerating cavities a decrease of the quality factor at lower fields - a so called \emph{low field Q slope or LFQS} - has been a long-standing unexplained effect. By extending the high $Q$…
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…
The presented results are part of a feasibility study of superheated superconducting microstructure detectors. The microstructures (dots) were fabricated using thin film patterning techniques with diameters ranging from $50\mu$m up to…
We report on our recent progress in the manipulation and cooling of a magnetically guided, high flux beam of $^{87}{\rm Rb}$ atoms. Typically $7\times 10^9$ atoms per second propagate in a magnetic guide providing a transverse gradient of…
We report specific heat measurements in neutron irradiated MgB2 samples, for which the critical temperature has been suppressed down to 8.5 K, but the superconducting transition remains extremely sharp, indicative of a defect structure…