| Title | Johnson noise thermometry measurements using a quantized voltage noise source for calibration |
| Publication Type | Journal Article |
| Year of Publication | 2003 |
| Authors | Nam, S.W., Benz S.P., Dresselhaus P.D., Tew W.L., White D.R., and Martinis J.M. |
| Journal | IEEE Transactions on Instrumentation and Measurement |
| Volume | 52 |
| Issue | 2 |
| Pagination | 550 - 554 |
| Date Published | 2003 |
| ISSN | 00189456 (ISSN) |
| Keywords | Calibration, Digital to analog conversion, Electric frequency control, Electric potential, Johnson noise thermometry, Josephson array, Josephson junction devices, Microwave devices, Signal noise measurement, Temperature measurement |
| Abstract | We describe a new approach to Johnson noise thermometry (JNT) that exploits recent advances in Josephson voltage standards and digital signal processing techniques. Currently, high-precision thermometry using Johnson noise is limited by the nonideal performance of electronic measurement systems. By using the perfectly quantized voltage pulses from a series array of Josephson junctions, any arbitrary broadband waveform can be synthesized and used as a calculable noise source for calibrating the cross-correlation electronics used in JNT systems. With our prototype JNT system, we have found agreement to two parts in 10 3 with a 1σ uncertainty of 1 × 10 -3 between the voltage noise of a 100-Ω resistor in a triple-point Ga cell (T 90 = 302.916 K) and a pseudo-noise waveform with the same average power that is synthesized by a quantized voltage noise source. We estimate the temperature of the resistor to be 302.5 K ± 0.3 K (1σ uncertainty based on the uncertainty from the cross-correlation). With better characterization of our JNT system, we expect to achieve relative accuracies of parts in 10 5 for arbitrary temperatures in the range between 270 and 1000 K. |
| URL | http://www.scopus.com/inward/record.url?eid=2-s2.0-0038236923&partnerID=40&md5=dbc76b8cc84cdc88b6b3a44b25fe5c09 |
| DOI | 10.1109/TIM.2003.811686 |
