23rd IMEKO TC 4 International Symposium and the 5th Chinese Conference on Electromagnetic Metrology Technical (IMEKO TC4 2019)

165 / 2019-03-16 02:08:15

Microvolt Josephson Voltage Standard Using a Dual-Channel Programmable Array Chip Developed at NIM

Josephson voltage standard,,nanovoltmeter,voltage measurement.,Josephson array

Plenary track > Calibration, Metrology and Standards

Previously a differential programmable Josephson voltage standard (DPJVS) has been developed for precision ultra low-voltage measurement of microvolt (μV) level at NIM. In this paper we present an updated technology for microvolt Josephson voltage standard (MJVS) which uses a dual-channel Josephson array chip with NbSi barrier developed at NIM. It is a new type device to build two symmetric paths of microwave irradiation for differential frequencies applying to a pair of channels of Josephson junction array. This new approach can efficiently simplify the complicated DPJVS system, which has two cryogenic systems, more expensive devices and is more difficult to operate. Based on it, a series of quantum-accurate microvolt voltages are achieved with uncertainty less than 1 nV, tens of times more accurate than the conventional technique. And the relevant precision measurement system has been established for calibration purpose. For practical application, a nanovolt meter has been successfully measured under the 10 μV range. Besides this, an improved 10 V PJVS is in progress to be improved in range and resolution when combining with the new standard based on the new dual-channel Josephson array chip.