The advancement of
optical technology demands the development of
chiral nanostructures with a strong dissymmetry of optical response.
Here, we comprehensively analyze the chiral optical properties of
circular twisted graphene nanostrips, with a particular emphasis on
the case of a Möbius graphene nanostrip. We use the method
of coordinate transformation to analytically model the electronic
structure and optical spectra of the nanostrips, while employing the
cyclic boundary conditions to account for their topology. It is found
that the dissymmetry factors of twisted graphene nanostrips can reach
0.01, exceeding the typical dissymmetry factors of small chiral molecules
by 1–2 orders of magnitude. The results of this work thus demonstrate
that twisted graphene nanostrips of Möbius and similar geometries
are highly promising nanostructures for chiral optical applications.