In one minute

Maia Neto, Rosa, Pires, Moraes, Canaguier-Durand and Guérout apply the scattering approach to the Casimir interaction between two dielectric half-spaces separated by an electrolyte. They include the nonlocal response created by mobile ions and add longitudinal channels, coupled to transverse ones by reflection at the dielectric surface. The interaction energy follows from the matrix describing a round trip of these coupled waves between the surfaces. For all nonzero Matsubara frequencies the electrolyte acts almost like a local medium, so those contributions are nearly unaffected by the ions. At zero frequency, longitudinal channels give a term screened over about a Debye length, while an unscreened transverse-magnetic term sets the long-distance limit of the interaction.

Scattering theory of the screened Casimir interaction in electrolytes