Positive Utilization; Excess Quasiparticle Injection in Superconducting Tunnel Junction X-ray Detector with Quasiparticle Trapping Layers

摘要

We report an anomalous x-ray detection property in a superconducting tunnel junction with quasiparticle trapping layers at high bias voltage. Being different from the conventional quasiparticle diffusion and edge loss model, the important characteristic parameters, such as a height and decay time of current pulse signals, are totally dependent on the incident position of photons and the applied bias voltage. This can be explained by the non-equilibrium state in a superconducting electrode induced by excess quasiparticle injection. We suppose that the property at high bias voltage should be advantageous for phonon detection and high count rate photon detection.