“…The former relates to the tunneling of electrons (quasiparticles) and results in the steps on the current-voltage curve as displaced in voltage by k ω/e; the latter assumes the supercurrent response, which occurs as the Shapiro steps at voltages k ω/2e (Nakamura et al, 2001). Both sets of resonances were observed experimentally and described theoretically in (Boris and Krasnov, 2015). In that study, it was demonstrated that the Shapiro steps and PAT states originate from Cooper-pair and quasiparticle currents; and if a JJ is subjected to an intense microwave signal, both sets of resonances can be observed in the current, changing both the voltage and microwave power (Boris and Krasnov, 2015;Snyder et al, 2018).…”