Graphene-insulator-superconductor junctions as thermoelectric bolometers

We design a superconducting thermoelectric bolometer made of a graphene-insulator-superconductor tunnel junction. Our detector has the advantage of being passive, as it directly transduces input power to a voltage without the need to modulate an external bias. We characterize the device via numerical simulation of the full nonlinear thermal dynamical model of the junction, considering heating of both sides of the junction. While estimating noise contributions, we found expressions due to the temperatures of both sides being different from the bath temperature. Numerical simulations show a noise equivalent power of approximately 4×10−17W/Hz1/2 for an input power of approximately 10−16W, a response time of approximately 200ns, and an integration time to obtain a signal-to-noise ratio of 1 of approximately 100μs for an input power of approximately 10−13W. Therefore, the device shows promise for large-array cosmological experiment applications, also considering its advantages for fabrication and heat budget.