Related papers: Resonance frequency measurement with accuracy and …
On May 20th 2019, the World Metrology Day, the Bureau International des Poids et Mesures announced a major revision to the four more SI units. The base unit, the kelvin, is defined by fixing the value of Boltzmann constant as indicated in…
To achieve an uncertainty of 0.25 mK in single-pressure refractive-index gas thermometry (SPRIGT), the relative pressure variation of He-4 gas in the range 30 kPa to 90 kPa, should not exceed 4 ppm (k=1). To this end, a novel pressure…
We introduce a spectroscopic approach to primary gas thermometry, harnessing precise optical cavity resonance frequencies and ab initio molecular line intensity calculations. By utilizing CO (3-0) vibrational band lines and cavity mode…
We have developed a low temperature, high-resolution microwave surface impedance probe that is able to operate in high static magnetic fields. Surface impedance is measured by cavity perturbation of dielectric resonators, with sufficient…
Dielectric resonators are employed to build state-of-the-art low-noise and high- stability oscillators operating at room and cryogenic temperatures. A resonator temperature coefficient of frequency is one criterion of performance. This…
We present a microwave-frequency method for measuring polar Kerr effect and spontaneous time-reversal symmetry breaking (TRSB) in unconventional superconductors. While this experiment is motivated by work performed in the near infrared…
We report on the realization of a high sensitivity RF noise measurement scheme to study small current fluctuations of mesoscopic systems at milliKelvin temperatures. The setup relies on the combination of an interferometric ampli- fication…
We studied noise properties of microwave signals transmitted through the cryogenic resonator. The experiments were performed with the 11.342 GHz sapphire loaded cavity resonator cooled to 6.2 K. Based on the measured transmission…
The development of a novel technique based on a cylindrical microwave resonator for high pressure phase equilibrium determination is described. Electric permittivity or dielectric constant is a physical property that depends on temperature…
Resistance thermometry is a time-tested method for taking temperature measurements. In recent years fundamental limits to resistance-based approaches spurred considerable interest in developing photonic temperature sensors as a viable…
Amplification is usually necessary when measuring the frequency instability of microwave signals. In this work, we develop a flicker noise free frequency measurement system based on a common or shared amplifier. First, we show that…
This paper presents a frequency synthesis that achieves exceptional stability by transferring optical signals to the radio frequency (RF) domain at 100 MHz. We describe and characterize two synthesis chains composed of a cryogenic silicon…
The accurate measurement of complex liquid permittivity in a frequency range provides important information on liquid properties in comparison to single frequency permittivity investigations. The multifrequency microwave characterization…
We apply the technique of far-field interferometry to measure the properties of surface waves generated by two-dimensional (2D) single subwavelength slit-groove structures on gold films. The effective surface index of refraction measured…
We describe the design and performance of a series of fast, precise current sensing noise thermometers. The thermometers have been fabricated with a range of resistances from 1.290 $\Omega$ down to 0.2 m$\mathrm{\Omega}$. This results in…
We have designed low noise temperature sensing and control units with the objective of using them for the fabrication of far infrared active cavity radiometers. The sensing unit, first characterized at 300K using industrial platinium…
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…
We report on the evaluation of microwave frequency synthesis using two cryogenic sapphire oscillators developed at the University of Western Australia. A down converter is used to make comparisons between microwave clocks at different…
We present the performances and the strain sensitivity of the first spherical gravitational wave detector equipped with a capacitive transducer and read out by a low noise two-stage SQUID amplifier and operated at a temperature of 5 K. We…
Squeezed states of light have been used extensively to increase the precision of measurements, from the detection of gravitational waves to the search for dark matter. In the optical domain, high levels of vacuum noise squeezing are…