Dispersive Thermometry with a Graphene Josephson Junction*

Graphene, with its vanishing heat capacity and weak electron-phonon coupling at cryogenic temperatures, is a promising material for ultrasensitive calorimetry and single-photon detection. Here, we present dispersive thermometry measurements performed on a tunable graphene Josephson Junction (gJJ) integrated into a resonant microwave circuit. In contrast to DC detection methods that rely on the switching of the gJJ to its resistive state, this approach allows for continuous temperature readout. We will discuss device operation and show results in both the electron- and hole-doped regimes. Our results represent a step towards fast detection of low-energy photons and phonons.