相关论文: Resonance frequency measurement with accuracy and …
We have developed a nuclear magnetic resonance spectrometer with a series tuned input circuit for measurements on samples at millikelvin temperatures based on an integrated two-stage superconducting quantum interference device current…
The accuracy of microwave measurements is not only critical for applications in telecommunication and radar, but also for future quantum computers. Qubit technologies such as superconducting qubits or spin qubits require detecting minuscule…
Optical frequency stabilization is a critical component for precision scientific systems including quantum sensing, precision metrology, and atomic timekeeping. Ultra-high quality factor photonic integrated optical resonators are a prime…
The direct detection of gravitational waves (GWs) of frequencies above MHz has recently received considerable attention. In this work we present a precise study of the reach of a cubic cavity resonator to GWs in the microwave range, using…
Microwave squeezing represents the ultimate sensitivity frontier for superconducting qubit measurement. However, observation of enhancement has remained elusive, in part because integration with conventional dispersive readout pollutes the…
We describe an instrument which can be used to analyze complex chemical mixtures at high resolution and high sensitivity. Molecules are collisionally cooled with helium gas at cryogenic temperatures (~ 4-7 K), and subsequently detected…
We report on the development of a sub-kelvin, single-crystal silicon Fabry-Perot cavity. Operating such a cavity below 1~K should reduce the thermal noise limit of the cavity, and by this way address the current limitations of ultrastable…
An increasing number of experiments require the use of ultrasensitive nanomechanical resonators. Relevant examples are the investigation of quantum effects in mechanical systems [1] or the detection of exceedingly small forces as in…
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…
Silicon photonic ring resonator thermometers have been shown to provide temperature measurements with a 10 mK accuracy. In this work we identify and quantify the intrinsic on-chip impairments that may limit further improvement in…
A new set-up to measure acoustic wave velocities through deforming rock samples at high pressures (up to 1000 MPa), temperatures (up to 700$^\circ$C) and differential stress (up to 1500 MPa) has been developed in a recently refurbished gas…
A wide variety of applications of microwave cavities, such as measurement and control of superconducting qubits, magnonic resonators, and phase noise filters, would be well served by having a highly tunable microwave resonance. Often this…
This paper deals with a single-crystal-silicon (SCS) MEMS resonator with improved temperature stability. While simulations have shown that the temperature coefficient of resonant frequency can be down to 1 ppm/degrees C, preliminary…
We present the design and commissioning of a cryogenic low-vibration test facility that measures displacement noise from a gram-scale silicon cantilever at the level of 10$^{-16}\, \mathrm{m/\sqrt{Hz}}$ at 1kHz. A volume of $\sim$36 litres…
The ion microwave frequency standard is a candidate for the next generation of microwave frequency standard with the potential for very wide applications. The Dick effect and second-order Doppler frequency shift (SODFS) limit the…
The refractive index of single microparticles is derived from precise measurement and rigorous modeling of the stiffness of a laser trap. We demonstrate the method for particles of four different materials with diameters from 1.6 to 5.2…
Results are reported from an experiment on RF pulsed heating of copper at SLAC. Damage in the form of cracks may be induced on the surface after the application of many pulses of RF. The experiment consists of two circularly cylindrical…
This paper presents a highly sensitive microwave sensor for dielectric sensing. One of the main disadvantages of microwave resonant-based sensors is cross-sensitivity originated by time-dependent uncontrolled environmental factors such as…
The theoretical model is fully developed and the test rig is designed for the measurements of microwave parameters of unclad and laminated dielectric substrates. The geometry of the electromagnetic field in the resonator allows dielectric…
A low level radio frequency (LLRF) control system is designed and constructed at Peking University, which is for the DC-SRF photo injector operating at 2K. Besides with continuous wave (CW), the system is also reliable with pulsed RF and…