Related papers: Wideband microwave measurements in Nb/Pd$_{84}$Ni$…
We studied a thin superconducting NbN film in magnetic fields up to 8 T above the zero- temperature limit by means of time-domain terahertz and scanning tunneling spectroscopies in order to understand the vortex response. Scanning tunneling…
In this work we discuss the use of interferometric measurement technique to study microwave magnetization dynamics on ferromagnetic nanostructures. We demonstrate that in this way one can resolve features which are impossible to resolve…
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…
Nb Superconducting Radio-Frequency (SRF) cavities are observed to break down and lose their high-Q superconducting properties at accelerating gradients below the limits imposed by theory. The microscopic origins of SRF cavity breakdown are…
We use a two-coil mutual inductance technique to investigate the non-linear response of the vortex lattice of two type-II superconducting thin films, namely a very weakly pinned amorphous Molybdenum Germanium (a-MoGe) and a…
Complex conductivity measurements spanning the entire temperature range, including the vicinity of $T_c$, were conducted on systematically varied FeSe$_{1-x}$Te$_x$ ($x$ = 0 - 0.5) very thin films. By applying a novel cavity measurement…
Controlled engineering of vortex pinning sites in copper-oxide superconductors is a critical issue in manufacturing devices based on magnetic flux quanta. To address this, we employed a focused He-ion beam (He-FIB) to irradiate thin…
The vortex dynamics in YBa2Cu3O7-d thin films have been studied at microwave frequencies. A pronounced peak in the surface resistance, Rs, is observed in these films at frequencies of 4.88 and 9.55 GHz for magnetic fields varying from 0.2…
The presence of quantum vortices determines the electromagnetic response of superconducting materials and devices. Controlling the vortex motion, their pinning on intrinsic and artificial defects is therefore essential for superconducting…
The vortex contribution to the dc field (H) dependent microwave surface impedance Z_s = R_s+iX_s of YBa_2Cu_3O_{7-x} thin films was measured using suspended patterned resonators. Z_s(H) is shown to be a direct measure of the flux density…
Superconducting Nb thin films with rectangular arrays of submicron antidots have been systemically investigated by transport measurements. In low fields, the magnetoresistance curves demonstrate well-defined dips at integral and rational…
As a part of my doctoral thesis, I studied the effect of phase fluctuations in two dimensional (2D) and three dimensional (3D) superconducting films of conventional s-wave superconductor, NbN, by measuring the electrodynamics response…
There is a renewed interest in superconductors for high-frequency applications, leading to a reconsideration of already known low-$T_c$ and high-$T_c$ materials. In this view, we present an experimental investigation of the millimeter-wave…
Among the recognized sources of decoherence in superconducting qubits, the spatial inhomogeneity of the superconducting state and the possible presence of magnetic-flux vortices remain comparatively underexplored. Niobium is commonly used…
We report measurements of the microwave surface impedance of the borocarbide family of superconductors LnNi2B2C (Ln=Y, Er, Tm, Ho). The experiments enable direct measurements of the superfluid density, and are particularly sensitive to the…
The response of superconducting devices to electromagnetic radiation is a core concept implemented in diverse applications, ranging from the currently used voltage standard to single photon detectors in astronomy. Suprisingly, a…
Niobium films are a key component in modern two-dimensional superconducting qubits, yet their contribution to the total qubit decay rate is not fully understood. The presence of different layers of materials and interfaces makes it…
Images of flux vortices in superconductors acquired by transmission electron microscopy should allow a quantitative determination of their magnetic structure but so far, only visual comparisons have been made between experimental images and…
The characteristic frequencies of a system provide important information on the phenomena that govern its physical properties. In this framework, there has recently been renewed interest in cryogenic microwave characterization for condensed…
The interplay between vortex guiding and the Hall effect in superconducting Nb films with periodically arranged nanogrooves is studied via four-probe measurements in standard and Hall configurations and accompanying theoretical modeling.…