Abstract

We demonstrate the electrical control of topological interface modes at the interface between a graphene-based photonic superlattice and a uniform dielectric medium. By integrating graphene sheets into the unit cell of metallodielectric superlattices, the presence or absence of topological interface modes can be dynamically controlled by tuning the permittivity of graphene via electrical gating. These modes emerge when the spatial average of the permittivity of the superlattices is negative and vanish when the chemical potential of graphene is adjusted to render the averaged permittivity positive. The existence of the interface modes is tied to a Dirac point at zero averaged permittivity and a Zak phase transition. The propagation constant of the topological interface modes decreases as the graphene chemical potential increases, and the modes are shown to be robust against structural disorder.

Abstract

We demonstrate the electrical control of topological interface modes at the interface between a graphene-based photonic superlattice and a uniform dielectric medium. By integrating graphene sheets into the unit cell of metallodielectric superlattices, the presence or absence of topological interface modes can be dynamically controlled by tuning the permittivity of graphene via electrical gating. These modes emerge when the spatial average of the permittivity of the superlattices is negative and vanish when the chemical potential of graphene is adjusted to render the averaged permittivity positive. The existence of the interface modes is tied to a Dirac point at zero averaged permittivity and a Zak phase transition. The propagation constant of the topological interface modes decreases as the graphene chemical potential increases, and the modes are shown to be robust against structural disorder.

Abstract

We demonstrate the electrical control of topological interface modes at the interface between a graphene-based photonic superlattice and a uniform dielectric medium. By integrating graphene sheets into the unit cell of metallodielectric superlattices, the presence or absence of topological interface modes can be dynamically controlled by tuning the permittivity of graphene via electrical gating. These modes emerge when the spatial average of the permittivity of the superlattices is negative and vanish when the chemical potential of graphene is adjusted to render the averaged permittivity positive. The existence of the interface modes is tied to a Dirac point at zero averaged permittivity and a Zak phase transition. The propagation constant of the topological interface modes decreases as the graphene chemical potential increases, and the modes are shown to be robust against structural disorder.

Abstract

We demonstrate the electrical control of topological interface modes at the interface between a graphene-based photonic superlattice and a uniform dielectric medium. By integrating graphene sheets into the unit cell of metallodielectric superlattices, the presence or absence of topological interface modes can be dynamically controlled by tuning the permittivity of graphene via electrical gating. These modes emerge when the spatial average of the permittivity of the superlattices is negative and vanish when the chemical potential of graphene is adjusted to render the averaged permittivity positive. The existence of the interface modes is tied to a Dirac point at zero averaged permittivity and a Zak phase transition. The propagation constant of the topological interface modes decreases as the graphene chemical potential increases, and the modes are shown to be robust against structural disorder.