Light-modulated graphene-based φ₀ Josephson junction and −φ₀ to φ₀ transition

We investigate the chiral edge states-induced Josephson current–phase relation in a graphene-based Josephson junction modulated by the off-resonant circularly polarized light and the staggered sublattice potential. By solving the Bogoliubov–de Gennes equation, a φ₀ Josephson junction is induced in the coaction of the off-resonant circularly polarized light and the staggered sublattice potential, which arises from the fact that the center of-mass wave vector of Cooper pair becomes finite and the opposite center of-mass wave vector to compensate is lacking in the nonsuperconducting region. Interestingly, when the direction of polarization of light is changed, −φ₀ to φ₀ transition generates, which generalizes the concept of traditional 0–π transition. Our findings provide a purely optical way to manipulate a phase-controllable Josephson device and guidelines for future experiments to confirm the presence of graphene-based φ₀ Josephson junction.