Heat current and noise in tunneling

Aalto Quantum Physics Seminar (Nanotalo). Speaker: Ms. Bayan Karimi (PICO, Aalto University, Finland).

In order to detect heat current over short timescales, we are developing fast and sensitive nanocalorimetry on low temperature nanostructures. We present non-invasive electron thermometry based on charge transport through a contact between a proximitized normal metal and a superconductor via a tunnel barrier. We demonstrate the advantages of supercurrent thermometry compared to traditional one in a wide range of biasing conditions. We estimate theoretically temperature fluctuations of a small metallic island under same conditions. By biasing an extra tunnel contact, we observe highly non-monotonous behavior of heat current and the associated fluctuations.