Quadratic Mixing of Radio Frequency Signals using Superconducting Quantum Interference Filters
arXiv:cond-mat/0602590 · doi:10.1063/1.2335368
Abstract
The authors demonstrate quadratic mixing of weak time harmonic electromagnetic fields applied to Superconducting Quantum Interference Filters, manufactured from high- grain boundary Josephson junctions and operated in active microcooler. The authors use the parabolic shape of the dip in the dc-voltage output around B=0 to mix \emph{quadratically} two external rf-signals, at frequencies and well below the Josephson frequency , and detect the corresponding mixing signal at . Quadratic mixing takes also place when the SQIF is operated without magnetic shield. The experimental results are well described by a simple analytical model based on the adiabatic approximation.
3 pages, 3 figures