Thermoelectric single-photon detection through superconducting tunnel junctions

Abstract

Bipolar thermoelectricity in tunnel junctions between superconductors of different energy gap has been recently predicted and experimentally demonstrated. This effect showed thermovoltages up to $\pm 150\mu$V at milliKelvin temperatures. Thus, superconducting tunnel junctions can be exploited to realize a passive single-photon thermoelectric detector $TED$ operating in the broadband range 15 GHz - 50 PHz. In particular, this detector is expected to show a signal-to-noise ratio of about 15 down to $\nu =50$ GHz and a operating window of more than 4 decades. Therefore, the $TED$ might find applications in quantum computing, telecommunications, optoelectronics, spectroscopy and astro-particle physics.

7 pages, 3 figures