Faílde, DanielBaldomir, Daniel2022-08-112022-08-112021Ann. Phys. (Berlin) 2022, 534, 2100313. https://doi.org/10.1002/andp.2021003130003-3804http://hdl.handle.net/10347/29054Topological 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 TIseng© 2021 The Authors. Annalen der Physik published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited Atribución 4.0 Internacionalhttp://creativecommons.org/licenses/by/4.0/AxionsCasimir effectTopological insulatorsjournal article10.1002/andp.2021003131521-3889open access