Boundary Element Method Simulations of Tunable Chiral Radiation and Active Chirality Switching from Rectangular Graphene Nanosheets: Implications for Dynamic Control of Light Chirality

Utilizing nanophotonic structures for chiral light–matter interactions has recently emerged as a highly promising scientific field, enabling a variety of novel applications. Carefully designed nanostructures can offer controllable photonic environments that can alter the chiral radiative properties of quantum emitters. It is thus crucial to obtain detailed knowledge and dynamic control over the properties of these nanostructures. In this work, the dynamically tunable plasmonic-induced chiral local density of states and radiation from a single and a dual graphene achiral nanostructure is demonstrated through boundary element method simulations, using electron beam excitations as well as plane waves. Highly efficient control over the chirality of the emitted light was obtained through small changes in the chemical potential of graphene, allowing active tuning and switching between linearly polarized and both left circularly polarized and right circularly polarized light, over a large wavelength range, and equally for local and nonlocal optical sources. Such efficient dynamic control of the ellipticity, optical rotation, handedness of light, and wavelength of the chiral radiation from a superthin nanoscale structure provides a way to realize optical nanodevices that can dynamically manipulate chiral light–matter interactions for a variety of nanophotonic applications.