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Publication Citation: Flat Frequency Response in the Electronic Measurement of the Boltzmann Constant

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Author(s): Jifeng Qu; Horst Rogalla; Yang Fu; Jianqiang Zhang; Alessio Pollarolo; Samuel P. Benz;
Title: Flat Frequency Response in the Electronic Measurement of the Boltzmann Constant
Published: June 01, 2013
Abstract: A new quantum voltage calibrated Johnson noise thermometer (JNT) was developed at NIM to demonstrate the electrical approach that determines the Boltzmann constant k by comparing electrical and thermal noise power. A measurement with an integration period of 19 hours and bandwidth of 638 kHz results in a relative offset of 1x10-6 from the current CODATA value of k, and type A relative standard uncertainty of 17x10-6. Closely matched noise powers and transmission-line impedances were achieved and resulted in a flat frequency dependence of the noise power ratio. Consequently, the quadratic fitting parameters of the ratio spectrum show flat frequency responses with respect to the measurement bandwidth. This flat response produces a dramatically reduced systematic error compared to that of the NIST measurement of k, in which the relative combined uncertainty was dominated by this error.
Citation: IEEE Transactions on Instrumentation and Measurement
Volume: 62
Issue: 6
Pages: pp. 1518 - 1523
Keywords: Boltzmann constant; Correlation;Johnson Noise; Josephson junction arrays; Noise;, Quantization; Thermometry;
Research Areas: SI (Electrical Units), Johnson Noise Thermometry, Quantum Devices, Superconducting Electronics, Quantum Electrical Measurements
DOI: http://dx.doi.org/10.1109/TIM.2013.2238431  (Note: May link to a non-U.S. Government webpage)
PDF version: PDF Document Click here to retrieve PDF version of paper (798KB)