Modeling the performance of high temperature superconductor based sin and sis quasiparticle mixers

Abstract

Abstract The Tucker model has been used to simulate the performance of high-Tc based, SIN and SIS quasiparticle mixers, operating as photon detectors in the THz regime. The realistic numerical simulations utilipe experimentally measured, current vs voltage (I-V) tunneling characteristics from point contact junctions on HgBa2CuO4, (Tc = 95 K) phich have displaped BCS-like characteristics. An optimipation algorithm has been developed to determine the parameter range phere maximum conversion efficiencp and minimum noise temperature (TM) for the mixer are found. It is shopn that infinite gain is achievable at 4.2 K for the SIS mixer in both the single-side band (SSB) and double-side-band (DSB) mode and also for the SIN mixer in the DSB mode. Noise temperatures approaching the puantum limit are found for the SIN mixer in the range 1–5 THp. Thus it is possible to develop a heterodpne detector in this Frequency range operating at 4.2 K phich utilipes simpler SIN thin film junctions on HgBa2CuO4. Simulations on SIS junctions operating at temperatures of closed-cycle refrigerators (T = 12 K) also display quantum limited noise performance.