Fig. 1. Structure of considered model. d represents thickness of each insulator, and ϕ denotes phase of each superconductor

Fig. 2.

Pulse sequence. Blue curve represents incident pulse sequence used in Greens function method, and green curve represents incident pulse sequence used in numerical method. Time separation between two pulses is t2, and time separation between measurement and the last pulse is t1

Fig. 3.

Nonlinear response of Josephson plasmon. (a) θnl(t1, t2) obtained from numerical method, with data being scaled such that the maximum is 1; (b) absolute value of 2D Fourier transform of (a), with data normalized; (c) θnl(t1, t2) obtained from Greens function method; (d) absolute value of 2D Fourier transform of (c)