Room temperature superconductivity dome at a Fano resonance in superlattices of wires.

Recently room temperature superconductivity with degrees Celsius has been discovered in a pressurized complex ternary hydride, CSH_x, which is a carbon- and hydrogen-doped H₃S alloy. The nanoscale structure of H₃S is a particular realization of the 1993 patent claim of superlattice of quantum wires for room temperature superconductors and the maximum T_C occurs at the top of a superconducting dome. Here we focus on the electronic structure of materials showing nanoscale heterostructures at the atomic limit made of a superlattice of quantum wires like hole-doped cuprate perovskites, and organics focusing on A15 intermetallics and pressurized hydrides. We provide a perspective of the theory of room temperature multigap superconductivity in heterogeneous materials tuned at a shape resonance or Fano resonance in the superconducting gaps near a Lifshitz transition focusing on H₃S where the maximum T_C occurs where the multiband metal is tuned by pressure near a Lifshitz transition. Here the superconductivity dome of T_C vs. pressure is driven by both electron-phonon coupling and contact exchange interaction. We show that the T_C amplification up to room temperature is driven by the Fano resonance between a superconducting gap in the anti-adiabatic regime and other gaps in the adiabatic regime. In these cases the T_C amplification via contact exchange interaction is the missing term in conventional multiband BCS and anisotropic Migdal-Eliashberg theories including only Cooper pairing. [ABSTRACT FROM AUTHOR]