Superconducting fluctuations in one-dimensional quasi-periodic “metallic” chains: the Little model of room-temperature superconductivity embodied

Abstract

It is well known that a purely periodic chain of odd-electron atoms, nominally expected to exhibit metallic behavior, is unstable to charge/spin spatial displacement which lowers its ground-state energy by gapping its highly degenerate Jahn–Teller Fermi surface, in this case consisting of nesting parallel Brillouin zone sheets. It is largely for these reasons that superconductivity has not been observed in highly one-dimensional metals—it is simply energetically more favorable for CDW/SDW gaps to form, via chain dimerization, rather than a BCS state, at the very least one mediated by electron–phonon coupling. In this paper, we explore the hypothetical electronic properties of a nominally “metallic” quasi-periodic chain using both an analytical approach and computationally via density functional theory, searching for configurations which could possibly yield “gap-lets” sufficiently small to permit the formation of BCS pairs as the new energetically favored ground state. The particular embodiment we examine is a proxy structure consisting of a string of odd-electron atoms with interatomic spacing following a Fibonacci sequence, positioned above the surface of an appropriate highly polarizable material substrate. We propose a path to its computational modeling followed by a route to synthesis of such a structure for experimental examination, and thus perhaps leading to an entirely new class of near-room-temperature superconductors.