Enhancement of superconductivity via resonant anti-shielding with topological plasmon-polarons

Stimulated by papers from the early 1970's, metallic metamaterial structures have recently been proposed to enhance the critical temperature of BCS superconductivity, Tc. That scheme requires a resonant, dynamic anti-shielding effect, which leads to a vanishing and negative nonlocal electronic dielectric function of the system. The conventional metamaterial can provide only a local analog of this effect, and so, as expected, experiments confirmed only very small Tc enhancements. Here we propose replacing the metamaterial structure with a film of a topological material (e.g. Bi2Se3), that supports a robust collective plasmon-polaron mode. We show, that the required very strong (resonant), dynamic anti-shielding can be induced in a superconductor interfaced with such a topological material film. A robust increase of Tc is possible, since this anti-shielding not only strengthens the electron pairing, but also renormalizes upwards the pairing interaction spectrum. We propose a superlattice arrangement of alternating superconductor-topological crystal layers as a realizable structure. Finally, we argue that similar enhancement might be expected in non-BCS superconductor systems.