Universal enhancement of superconductivity in two dimensional semiconductors at low doping by electron-electron interaction

Abstract

In two-dimensional multivalley semiconductors, at low doping, even a moderate electron-electron interaction enhances the response to any perturbation inducing a valley polarization. If the valley polarization is due to the electron-phonon coupling, the electron-electron interaction results in an enhancement of the superconducting critical temperature. By performing first principles calculations beyond density functional theory, we prove that this effect accounts for the unconventional doping-dependence of the superconducting transition-temperature (T${}_c$) and of the magnetic susceptibility measured in Li${}_x$ZrNCl. By finding the conditions for a maximal T${}_c$ enhancement, we show how weakly-doped two-dimensional semiconductors provide a route towards high T${}_c$ superconductivity.

5 Pages + Supplementary materials, 9 Pictures overall, to appear on Phys. Rev. Lett

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• Valley susceptibility of an interacting two-dimensional electron system
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Cited by in corpus (5)

• Gate-controlled BCS-BEC crossover in a two-dimensional superconductor
• Revisiting the homogeneous electron gas in pursuit of the properly normed ab initio Eliashberg theory
• High-$T_c$ superconductivity in weakly electron-doped HfNCl
• Enhancement of Superconductivity upon reduction of carrier density in proximitized graphene
• Variational formulation of dynamical electronic response functions in presence of nonlocal exchange interactions