Related papers: A semi-empirical model for two-level system noise …
Designing quantum systems with the measurement speed and accuracy needed for quantum error correction using superconducting qubits requires iterative design and test informed by accurate models and characterization tools. We introduce a…
We present simulations and analytic calculations of the electromagnetic microwave fields of coplanar waveguide (CPW) resonators in the vicinity of highly conducting metallic samples. The CPW structures are designed with the aim of…
We investigate the microwave electrodynamic properties of a single superconducting thin film split-ring resonator (SRR). The experiments were performed in an all-Nb waveguide, with Nb wires and Nb SRRs. Transmission data showed a high-Q…
Resistance noise spectroscopy is applied to bulk single crystals of the quasi-two-dimensional organic Mott insulator $\kappa$-(BEDT-TTF)$_2$Cu[N(CN)$_2$]Cl both under moderate pressure and at ambient-pressure conditions. When pressurized,…
The electronic properties of superconducting Sn films ($T_c \approx$ 3.8 K) change significantly when reducing the film thickness down to a few nm, in particular close to the percolation threshold. The low-energy electrodynamics of such Sn…
We have used Ramsey tomography to characterize charge noise in a weakly charge-sensitive superconducting qubit. We find a charge noise that scales with frequency as $1/f^\alpha$ over 5 decades with $\alpha = 1.93$ and a magnitude…
Materials imperfections in Nniobium based superconducting quantum circuits, in particular, two-level-system (TLS) defects, are a major source of decoherence, ultimately limiting the performance of quantum computation and sensing. Thus,…
Microresonators are powerful tools to enhance the efficiency of second-order nonlinear optical processes, such as second-harmonic generation, which can coherently bridge octave-spaced spectral bands. However, dispersion constraints such as…
We investigated both theoretically and experimentally open-ended coplanar waveguide resonators with rf SQUIDs embedded in the central conductor at different positions. These rf SQUIDs can be tuned by an external magnetic field and thus may…
We present non-conventional electron spin resonance (ESR) experiments using microfabricated superconducting waveguides. We show that a very broad frequency range, from 0.5 to 40 GHz, becomes accessible with a high frequency accuracy of less…
We demonstrate the generation of a low-noise, octave-spanning mid-infrared supercontinuum from 1700 to 4800 nm by injecting femtosecond pulses into the normal dispersion regime of a multimode step-index chalcogenide fiber with 100 $\mu$m…
We report the measurement of the fluctuations of a transmon qubit through the noise spectrum of the microwave signal that measures its state. The amplitude of the Lorentzian noise power spectrum allows to determine the average qubit…
This paper presents a very simple analytical model for the design of Frequency Selective Surfaces based on Complementary Split Ring Resonators (CSRR) within the microwave range. Simple expressions are provided for the most important…
Signal to noise ratios (SNR) in magnetic resonance microscopy images are limited by acquisition times and the decreasing number of spins in smaller voxels. Significant SNR gains from cooling of the RF receiver are only realized when the…
Two nominally identical ultra-stable cryogenic microwave oscillators are compared. Each incorporates a dielectric-sapphire resonator cooled to near 6 K in an ultra-low vibration cryostat using a low-vibration pulse-tube cryocooler. The…
Hybrid superconducting--spin systems offer the potential to combine highly coherent atomic quantum systems with the scalability of superconducting circuits. To fully exploit this potential requires a high quality-factor microwave resonator,…
Superconducting enclosures will be key components of scalable quantum computing devices based on circuit quantum electrodynamics (cQED). Within a densely integrated device, they can protect qubits from noise and serve as quantum memory…
We introduce a novel stochastic model for charge noise in superconducting charge qubits based on memory multi-fractional Brownian motion (mmfBm), capable of capturing non-stationary and long-memory effects. This framework reproduces key…
We consider the stray magnetic field noise outside a two-dimensional superconductor. Our considerations are motivated by recent experiments, which observed an enhancement in the magnetic field noise below the superconducting critical…
We discuss the prospects of employing an NbN superconducting microwave stripline resonator for studying the dynamical Casimir effect experimentally. Preliminary experimental results, in which optical illumination is employed for modulating…