Linking AC quantum systems using a thermal converter

The National Institute of Standards and Technology (NIST) has developed two types of ac sources that rely on Josephson Junction Arrays to provide quantum-accurate voltage. The pulsed-programmable AC Josephson Voltage Standard (ACJVS) and the Programmable Josephson Voltage Standard (PJVS) used as the basis for the NIST Quantum Watt can both be used to provide quantum accurate ac signals; however, owing to hardware limitations, the output frequencies available do not overlap. We have used a thermal transfer standard with negligible frequency coefficient to link the two AC quantum standards. We describe the experiment, present the results, and describe plans to use these systems as the basis for ac voltage and current metrology at NIST.