On-chip Josephson junction-based sensor for temperature control of a cryocooled quantum standard

In this paper we show how an overdamped Josephson junction can be exploited as temperature sensor in a closedloop circuit to control the operating point of a cryocooled device, e.g. a quantum standard. The resistance of a Josephson junction is measured at the desired temperature with a commercial ac resistance meter, that then uses this value to regulate the chip temperature via its own PID control functionality. Experimental setup and measurement methods are described here. Moreover, the temperature sensitivity of an ideal junction has been determined for different bias-current values.