Can Negative Capacitance Induce Superconductivity?

Abstract

Superconductivity was originally observed in 3D metals caused by an effective attraction between electrons mediated by the electron-phonon interaction. Since then there has been a lot of work on 2D conductors including the possibility of alternative mechanisms that can lead to an effective attractive interaction. Inspired by the experimental demonstration of both steady-state and transient negative capacitance in a variety of structures, this paper investigates the possibility of superconductivity in a two-dimensional conductor embedded in a negative permittivity medium whose role is to turn the normally repulsive Coulomb interaction into an attractive one. A weak coupling BCS theory is used to identify the key parameters that have to be optimized to observe a superconducting transition, especially the need for a small effective negative permittivity, which could be obtained by balancing a negative permittivity medium with a positive permittivity one.