Title :
The quantum roulette noise thermometer
Author :
Hao, Ling ; Gallop, John C. ; Macfarlane, John C. ; Peden, Derek A. ; Reed, Richard P.
Author_Institution :
Centre for Basic & Thermal Metrol., Nat. Phys. Lab., Teddington, UK
fDate :
4/1/1999 12:00:00 AM
Abstract :
A novel form of primary thermometer called the quantum roulette noise thermometer (QRNT), based on flux quantization in a high temperature superconducting (HTS) ring, interrupted by a Josephson junction, has been proposed. The basis of the QRNT is that the flux state of the ring is allowed to evolve freely, and is repeatedly interrogated to establish a probability distribution from which the temperature of the device is derived. Unlike other superconductivity-based noise thermometers, this device is essentially dissipationless, requires no input or output connections, and may be remotely interrogated. The QRNT has the potential to provide high accuracy with short measuring times. Prototype QRNT devices based on thin HTS films have been fabricated and results of initial experimental measurements are presented. Parameters of the experimental devices are compared with predictions of the theoretical model
Keywords :
Gaussian noise; SQUID magnetometers; fluctuations in superconductors; flux-line lattice; superconducting device noise; temperature scales; thermal noise; thermometers; Gaussian noise; HTSC ring; Josephson junction; Nyquist noise; cosine modulated Gaussian distribution; flux quantization; high accuracy; primary thermometer; probability distribution; quantum roulette noise thermometer; readout SQUID; remotely interrogated; High temperature superconductors; Josephson junctions; Predictive models; Probability distribution; Prototypes; Quantization; Superconducting device noise; Superconducting films; Superconductivity; Temperature distribution;
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
