On the Bipolaronic Mechanism of High-Temperature Superconductivity in "Ginzburg Sandwiches" FeSe-SrTiO<sub>3</sub>; SrTiO<sub>3</sub>-FeSe-SrTiO<sub>3</sub>

The mechanism of experimentally observed high-temperature superconductivity (HTSC) in thin FeSe films on SrTiO3-type substrates has been theoretically investigated. Applying the theory large-radius bipolaronic states developed based exact Hamiltonian electron-phonon interaction for arbitrary multilayer structures, Cooper pairing polarons monolayers SrTiO3 is investigated and three-layer structures SrTiO3–FeSe–SrTiO3, which are typical "Ginzburg sandwiches". Approach proposed by Ginzburg to enhance achieve HTSС separating regions where electrons located (forming pairs or bipolarons) with excitons excited (or inertial polarization induced), made it possible implement criteria formation high binding energy, due possibility selecting optimal geometric material parameters (layer thicknesses, dielectric permittivity, optical frequencies, effective masses). It shown that energy bipolarons (Ebp) these range values remain stable quasiparticles can exist at temperatures significantly higher than their Bose condensation temperature. monolayer substrate provides emergence a HTS critical temperature (Tc) more an order magnitude Tc massive crystals. At same time, bipolaron layer thickness d increases exponentially decreasing (Ebp~exp(-d / RS) RS radius polaron) reaches its maximum value limit film (d→0). presented allows modeling system determining layers forming structure large number room be achieved.