2014/08/16 by Yiwen Wang, Pinjia Zhou, Pin-Jia Zhou +8 · 8 citations
Computer Science · Physics and Astronomy · #Condensed matter physics #Cooper pair #Current (fluid) #Josephson effect #Materials science #Noise (video) #Optics #Optoelectronics #Photon #Photon energy #Physics #Physics of Superconductivity and Magnetism #Quantum Information and Cryptography #Radiation #Superconducting and THz Device Technology #Superconductivity #cond-mat.mes-hall
paper · pdf · doi:10.1016/j.physc.2015.05.005
published in Physica C Superconductivity 515, 49-53 (Elsevier BV)
arxiv created 2014/08/16 · openalex publication_date 2015/05/29 · openalex created_date 2016/06/24 · arxiv updated 2017/02/28 · openalex updated_date 2026/08/05
We experimentally demonstrated the optical responses of the switching currents in two types of Josephson tunnel junctions: Al/AlOx/Al and Nb/AlOx/Nb. The radiation-induced switching current shifts were measured at ultra-low bath temperature (T~16 mK). It is observed that the Al-junction has a more sensitive optical response than the Nb-junction, which is as expected since Al electrode has a smaller superconducting gap energy. The minimum detectable radiation powers with the present Al-junction and Nb-junction are 8 pW (corresponding to 8*105 incoming photons in one measurement cycle) and 2 nW respectively. In addition, we found that the radiation-induced thermal effects are dominant in the observed optical responses. Several methods are proposed to further improve the optical responsivity, so that the josephson junction based devices could be applicable in photon detections.