Simulation of THz oscillations in an intrinsic Josephson junction array

Abstract

When a voltage is applied to coupled Josephson junctions, an ac current flows because of the Josephson effect. Due to this ac current, an electromagnetic (EM) wave is emitted from junctions. For the cuprate High-Tc superconductor, frequency of the EM wave reaches to the THz regime since the energy gap is large. In order to simulate the EM wave in the superconductors, we solve the Josephson junction relations and the Maxwell equations simultaneously. Especially, we consider coupling of junctions including capacitive and inductive couplings, and spatial variations of phase differences of order parameters inside of junctions. We shows time developments of distributions of the phase differences, magnetic and electric fields in junctions in the transient state.