Graphene-based Josephson parametric amplifiers for highly sensitive bolometry*

Sensitive, broadband bolometers are of great interest because of their versatile usage in broad areas starting from radio astronomy, material science, and security development research. To date, the widely used sensitive bolometers are transition edge sensors and kinetic inductance detectors which provide a noise equivalent power (NEP) of ~ 500 zW/√Hz. Recently 2D vdW material-based bolometers have improved the NEP and response time by exploiting the material properties, however, the NEP can be further upgraded by improving the sensitivity and intrinsic noise level of the sensors. The Josephson parametric amplifiers (JPA) are the routinely used devices for low-noise amplification of quantum signals in cQED experiments, which boost the signal-to-noise ratio significantly. Our recent work demonstrates the implementation of a gate-tunable JPA using a graphene Josephson junction, where we change the device bias using electrostatic gating [1]. Electrostatic control is advantageous over magnetic flux control in cQED devices as it uses a very localized electric field which causes less interference. In addition and in contrast with the Al-based tunnel junctions, the attractive material properties of graphene: low heat capacity, and low electron-phonon coupling, imply a single-photon detector integrated with the quantum noise limited amplifier is realizable using our device. In this talk, we will discuss the bolometric response of our graphene JPA device.