Limiting Characteristics of Classical Josephson Detector

Abstract

Analytical and numerical calculations of limiting characteristics of electromagnetic radiation detectors based on Josephson junctions are carried out. Josephson junctions are described by a simple resistively shunted model and their Josephson energy is considered to be comparable to the energy of thermal fluctuations. The operation modes of such junctions as a classical detector using ac rectification on a static nonlinear current–voltage characteristic are established. The results of numerical and analytical calculations are compared, and it is shown that the classical detection mode can be analyzed and optimized using the derived analytical expressions for the main limiting characteristics. The study demonstrates the possibility of achieving a limiting sensitivity up to 2 × 10^–15 W/Hz^1/2, a dynamic power range of 10⁵–10⁶, and a spectral range up to 1.4 THz, in a temperature range 50–77 K using new Josephson thin-film junctions consisting of high-temperature YBa₂Cu₃O_7 – x superconductors with mutually tilted c axes.