English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The opacity of graphene is known to be approximately given by thefine-structure constant $\alpha$ times $\pi$. We point out the fact that theopacity is roughly independent of the frequency and polarization of the lightcan be attributed to the topological charge of the Dirac points. As a result,one can literally see the topological charge by naked eyes from the opacity ofgraphene, and moreover it implies that the fine-structure constant istopologically protected. A similar analysis suggests that 3D topologicalinsulator thin films of any thickness also have opacity $\pi\alpha$ in theinfrared region owing to the topological surface states, indicating that onecan see the surface states by naked eyes through an infrared lens. For 3D Diracor Weyl semimetals, the optical absorption power is linear to the frequency inthe infrared region, with a linearity given by the fine-structure constant andthe topological charge of Weyl points.

Opacity of graphene independent of light frequency and polarization due to the topological charge of the Dirac points