To date the most sensitive detectors for electro-magnetic radiation are based on superconducting materials and exploit local photo-induced heating across their strongly temperature dependent superconducting transition. The allegedly unconventional superconducting phase of magic-angle twisted bilayer graphene (MATBG) has been predicted to possess extraordinary thermal properties, as it is formed from a highly diluted electron ensemble with both a record-low carrier density n ~ 10^11 cm-2 and electronic heat capacity Ce < 100 kB. While these attributes position MATBG as a ground-breaking material platform for revolutionary calorimetric applications, these properties have so far not been experimentally shown. In this study we reveal the ultra-sensitive calorimetric properties of a superconducting MATBG device and establish it as a revolutionizing active material for ultra-sensitive photon-detection applications.
Tullio Scopigno