We investigate particle–antiparticle pair creation in a vacuum under strong electromagnetic fields, interpreting it as a field-induced phase transition characterized by spontaneous symmetry breaking. Using the quasi-particle representation of the quantum kinetic equation, we analyze the evolution of the complex order parameter \( \varPhi (p, t) \) in a sequence of Sauter pulses with time delay. Our study reveals modified evolution stages, from quasi-electron-positron plasma oscillations to a residual plasma via a highly non-linear transient region. Furthermore, we examine entropy dynamics, showing a correlation between entropy density and the order parameter’s modulus, leading to a non-monotonic entropy evolution.