Related papers: Niobium Quarter-Wave Resonator Development for The…
The in-plane motion of an electron on helium can couple to superconducting microwave resonators via electrical dipole coupling, offering a robust and rapid readout scheme. In previous efforts, microwave resonator designs for electrons on…
Two dimensional materials are becoming increasingly popular as a platform for studies of quantum phenomena and for the production of prototype quantum technologies. Quantum emitters in 2D materials can host two level systems that can act as…
Radio frequency (RF) acoustic resonators have long been used for signal processing and sensing. Devices that integrate acoustic resonators benefit from their slow phase velocity (vp), in the order of 3 to 10 km/s, which allows…
Surface acoustic wave (SAW) resonators provide a compact platform for confining microwave-frequency phonons and are widely used in radio-frequency technologies, but their operation at gigahertz frequencies and cryogenic temperatures remains…
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 use inelastic neutron scattering to probe magnetic excitations of an optimally electron-doped superconductor Nd$_{1.85}$Ce$_{0.15}$CuO$_{4-\delta}$ above and below its superconducting transition temperature $T_c=25$ K. In addition to…
Using a fully automated cryogenic wafer prober, we measured superconductor fabrication process control monitors and simple integrated circuits on 200 mm wafers at 4.4 K, including SQIF-based magnetic field sensors, SQUID-based circuits for…
The research note presents results of coupled RF and thermal simulation of a cryocooler conduction cooled 650 MHz SRF cavity made of bulk niobium and coated with Nb3Sn on the RF surface. The cavity is part of a particle accelerator design…
The coherence of state-of-the-art superconducting qubit devices is predominantly limited by two-level-system defects, found primarily at amorphous interface layers. Reducing microwave loss from these interfaces by proper surface treatments…
We report on the design and performance of a cryogenic (300 mK) near-field scanning microwave microscope. It uses a microwave resonator as the near-field sensor, operating at a frequency of 6 GHz and microwave probing amplitudes down to 100…
We consider a simple model of a Josephson junction phase qubit coupled to a solid-state nanoelectromechanical resonator. This and many related qubit-resonator models are analogous to an atom in an electromagnetic cavity. When the systems…
We propose a realizable architecture using one-dimensional transmission line resonators to reach the strong coupling limit of cavity quantum electrodynamics in superconducting electrical circuits. The vacuum Rabi frequency for the coupling…
Millimeter-wave superconducting resonators are a useful tool for studying quantum device coherence in a new frequency domain. However, improving resonators is difficult without a robust and reliable method for coupling millimeter-wave…
Long-lived mechanical resonators like drums oscillating at MHz frequencies and operating in the quantum regime are a powerful platform for quantum technologies and tests of fundamental physics. Yet, quantum control of such systems remains…
We study a cross-shaped cavity filled with superfluid $^4$He as a prototype resonant-mass gravitational wave detector. Using a membrane and a re-entrant microwave cavity as a sensitive optomechanical transducer, we were able to observe the…
We report on the detection of a kilohertz quasi-periodic oscillation (QPO) with the Neutron Star Interior Composition Explorer (NICER). Analyzing approximately 165 ks of NICER exposure on the X-ray burster 4U 0614+09, we detect multiple…
The problem of finding the optimal current distribution supported by small radiators yielding the minimum quality (Q) factor is a fundamental problem in electromagnetism. Q factor bounds constrain the maximum operational bandwidth of…
We have built and evaluated a prototype quantum radar, which we call a quantum two-mode squeezing radar (QTMS radar), in the laboratory. It operates solely at microwave frequencies; there is no downconversion from optical frequencies.…
Titanium and niobium are the main materials used for the fabrication of Superconducting Radio Frequency (SRF) cavities. These two metals are usually joined , using various welding techniques, using a third material in between. This…
We demonstrate an ultralow loss monolithic integrated lithium niobate photonic platform consisting of dry-etched subwavelength waveguides. We show microring resonators with a quality factor of 10$^7$ and waveguides with propagation loss as…