Nonlinear Dynamics of a Hybrid Josephson Heterostructure with Cuprate Antiferromagnetic Interlayer

Abstract

The nonstationary Josephson effect in a hybrid heterostructure based on the YBa₂Cu₃O_7–δ cuprate superconductor and cuprate antiferromagnetic barrier interlayer Ca_0.5Sr_0.5CuO₂ and with the upper superconducting electrode Au/Nb is experimentally investigated. At the frequency of external exposure f = 70 GHz, close to the plasma frequency of the Josephson junction, a giant increase in the noise signal was detected, which was explained by the appearance of stochastic oscillations on the heterostructure. Stochastic oscillations, but with less intensity, occur at the frequency f = 45 GHz. At the same time, on the current–voltage characteristics, there are intervals with negative dynamic resistance.