PTB JAWS chips distributed to Russia, China and Turkey

Chips for the pulse-driven Josephson Voltage Standard (JAWS) are distributed to metrology institutes in Russia, China and Turkey within the framework of international research cooperation.

The pulse-driven AC Josephson voltage standard enables the generation of arbitrary and spectrally pure waveforms, and it is referred to as Josephson arbitrary waveform synthesizer (JAWS). Essential components of the JAWS are series arrays of SNS Josephson junctions (SNS: superconductor – normal conductor – superconductor). The circuits are fabricated in the PTB clean-room facility in a modified window-type process. Hereby, niobium serves as superconductor and Nb_xSi_1-x as barriers.
At PTB these JAWS circuits are investigated and further developed for several applications in 6 JAWS systems. Within the framework of international research projects (EMPIR) the JAWS chips are already used at different European metrology institutes, e.g. VSL, NPL, INRIM, JV, VTT.

Within bilateral research cooperations, these circuits are now distributed to more metrology institutes: TUBITAK (Turkey), VNIM (Russia), BIRMM (China). For the successful operation of these chips an optimized experimental setup is necessary, including the software control. The PTB will assist these institutes here too. To manage the handling of a complete JAWS system for practical use in the laboratory, an intensive training was performed at PTB.

The experience gained by operation of these JAWS systems will be shared with PTB and common publication are planned.

Figure 1: Three-week training at the 1.5 V JAWS system at PTB with 5 members of the Chinese BIRMM Institute (Beijing) in September 2018.