Single-photon detection using magnesium diboride superconducting nanowires

Abstract

We fabricated 10 nm thick ${\text{MgB}}_2$ nanowires with a width down to 100 nm using the liftoff process. The $I\text{-}V$ characteristics of the nanowire show hysteresis and a sharp voltage jump at $I_c$ . Though a 150 nm wide nanowire exhibits the capacity for detecting a single photon at 405 nm wavelength, the nanowire is too wide to detect a single photon at 1560 nm. A 100 nm wide nanowire exhibits the capacity for detecting single photons in the 405–1560 nm wavelength range. This indicates a possible application of ${\text{MgB}}_2$ as a high-performance superconducting nanowire single-photon detector.