Detection of single infrared photons in superconducting microstrips of 4 nm thick disordered Nb0.15Re0.85 has been investigated. Microstrips with a critical temperature of 5.15 K and widths from 1.0 to 2.5 μm have been fabricated by optical lithography. We demonstrate single photon detection sensitivity at 1.5 μm wavelength at a temperature of 1.79 K. By investigating the detection process at this temperature, we find that the current bias threshold is at 21% of the depairing current. This threshold is similar to what should be observed in typical amorphous superconductors, which confirms that ultrathin disordered Nb0.15Re0.85 is an interesting material for superconducting microstrip single photon detectors that operate above 1 K.
Single photon detection in NbRe superconducting microstrips / Ejrnaes, M.; Cirillo, C.; Salvoni, D.; Chianese, F.; Bruscino, C.; Ercolano, P.; Cassinese, A.; Attanasio, C.; Pepe, G. P.; Parlato, L.. - In: APPLIED PHYSICS LETTERS. - ISSN 0003-6951. - 121:26(2022), p. 262601. [10.1063/5.0131336]
Single photon detection in NbRe superconducting microstrips
Cirillo C.;Salvoni D.;Chianese F.;Bruscino C.;Ercolano P.;Cassinese A.;Pepe G. P.;Parlato L.
2022
Abstract
Detection of single infrared photons in superconducting microstrips of 4 nm thick disordered Nb0.15Re0.85 has been investigated. Microstrips with a critical temperature of 5.15 K and widths from 1.0 to 2.5 μm have been fabricated by optical lithography. We demonstrate single photon detection sensitivity at 1.5 μm wavelength at a temperature of 1.79 K. By investigating the detection process at this temperature, we find that the current bias threshold is at 21% of the depairing current. This threshold is similar to what should be observed in typical amorphous superconductors, which confirms that ultrathin disordered Nb0.15Re0.85 is an interesting material for superconducting microstrip single photon detectors that operate above 1 K.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
