Frequency-selective incoherent detection of terahertz radiation by high-$Tc$ Josephson junctions Available to Purchase

The detector response of $YBa2Cu3O7−x$ Josephson grain-boundary junctions to monochromatic radiation with the frequency f in the range from 60 GHz to 4 THz has been studied. Frequency-selective odd-symmetric resonances in the responses $ΔI(V)$ of these junctions to radiation with different frequencies f have been observed near the voltages $V=hf/2e$ in almost a decade of spectral range for any operating temperature in the range from 30 to 85 K. The spectral range of the selective detection has scaled with the $IcRn$ product of the Josephson junction, reaching the range of 0.16–3.1 THz for a $IcRn$ product of 1.5 mV. A resolving power $δf/f$ of around $10−3$ has been demonstrated in the selective detection by Josephson junctions. The high-frequency falldown of the amplitude of the selective response has been found to be proportional to $exp[−P/P0],$ where $P=(hf/2e)2/Rn$ is the power dissipated in the junction at the resonance and $P0$ is a characteristic power level. The values of $P0$ for our junctions were around 20 μW at 34 K and 2 μW at 78 K.