Optical bistability in graphene-wrapped dielectric nanowires

We study the optical bistability of graphene-wrapped dielectric cylinders with Kerr-type nonlinear response within the framework of both nonlinear full-wave scattering theory and nonlinear quasistatic theory. Typical optical bistable properties are observed in both near-field and far-field spectra with the excitation of electric dipolar modes. Moreover, when high electromagnetic field is applied, nonlinear full wave theory yields new bistable region, indicating the existence of an artificial tunable magnetic dipole. The switching threshold fields are found to be tunable by changing either the size, permittivity of the nanocylinder or the chemical potential of graphene. Our results offer insight into the interaction between Kerr-type nonlinearity and graphene plasmonics, and may promise the graphene-wrapped nanowire a candidate for all-optical switching and nano-memories in terahertz region.