Measurements of absolute temperature below 0.75 K using a Josephson-junction noise thermometer

Review of temperature measurement

“…The type of circuitry used depends on the temperature range and was reviewed by Kamper, 101 by Blalock and Shepard, 102 and by White et al 103 For low temperature measurements, at less than 1 K, two types of absolute noise thermometers have proved useful according to Soulen et al 104 Both measure the noise voltage generated by a resistor using a superconducting quantum interference device ͑SQUID͒. In one type the resistor is inductively coupled to the SQUID.…”

Simulation and Measurement of HTS Josephson Heterodyne Oscillator

“…It is noteworthy that R-SQUIDs made from low-temperature-superconducting thin films, e.g. Niobium, in which the tunnel barrier is relatively free of such defects, show greatly reduced, even negligible, linewidth broadening, and for this reason, have been serious contenders for the realization of an absolute noise thermometer [9].…”

The Roles of the Mise en Pratique for the Definition of the Kelvin

“…The first, based on a noisevoltage measurement using cross correlators, has been used to measure temperatures in the range from a few kelvins to 2500 K. Although it provides useful experimental validation of other methods (e.g., [17,18]), it cannot easily achieve the low relative uncertainties (<0.002 %) obtainable with other direct methods such as acoustic gas thermometry. The second class of noise thermometer is based on noise measurement using superconductive quantum interference devices (SQUID) at temperatures of a few kelvins down to a few millikelvins [19][20][21][22]. At these temperatures where relative uncertainties of 0.1 % are very useful, a well-behaved, primary noise thermometer has considerable appeal.…”