On the Inner Topological Pressure within the Topological Insulators

Topological insulators (TIs) have axion electrodynamics instead of the usual Maxwell. Then, there is an additional energy density, whose origin is topological, generating a pressure that is found analytically. It is shown that the topological electric and magnetic fields act only on the surface, while the scalar axion does as a real Klein-Gordon field in all the TI, giving rise to a behavior quite similar to the Casimir effect without the intervention of the virtual photons of the vacuum. This opens the possibility to experimentally test the electrodynamics of axions for the TIs.

Automated summary

Topological insulators exhibit axion electrodynamics instead of the usual Maxwell equations, leading to unique behaviors in electric and magnetic fields. The research shows that the topological electric and magnetic fields only affect the surface, while the scalar axion behaves like a real Klein-Gordon field throughout the topological insulator. This opens up the possibility of experimental testing of axion electrodynamics in topological insulators.