Can Negative Capacitance Induce Superconductivity?

TL;DR

This paper explores the potential for inducing superconductivity in 2D conductors by embedding them in a negative permittivity medium, which could turn Coulomb repulsion into attraction, using a weak coupling BCS framework.

Contribution

It proposes a novel mechanism for superconductivity via negative capacitance in 2D materials, highlighting key parameters for experimental realization.

Findings

Negative permittivity can induce attractive interactions in 2D conductors.

Small effective negative permittivity is crucial for superconductivity.

Balancing negative and positive permittivity media is necessary for optimal conditions.

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.