# Photoinduced Screening Breakdown Mediated by Plasmon Excitations and Potential Instabilities in the System

## TL;DR

This paper investigates how photoinduced plasmon excitations can cause screening breakdown and potential instabilities like superconductivity or charge density waves in electron systems, revealing a new mechanism for electron interaction renormalization.

## Contribution

It introduces a novel analysis of Coulomb potential oscillations and instabilities induced by plasmon excitations, considering divergence effects in electron permittivity.

## Key findings

- Coulomb potential acquires oscillating terms leading to spatial heterostructures.
- Resonant plasmon excitation can make Coulomb interaction attractive at small momenta.
- Potential divergence of electron coupling constant suggests new superconductivity mechanisms.

## Abstract

In this work, we estimate the effect of photoinduced screening breakdown of the Coulomb potential mediated by plasmons. In contrast to previous studies, we consider the contribution from the divergence of renormalized inverse electron permittivity, which enhances Coulomb interaction at longer ranges. Our work reveals that the Coulomb potential acquires oscillating terms, which for the charged plane case could lead to a spatial heterostructure. In the resonant case ($\omega_p = \Omega$), photoinduced Coulomb interaction becomes attractive for small values of momenta. This Coulomb interaction renormalization could potentially lead to instabilities in the electron system, such as superconductivity and/or charge density waves. We found possible divergence of the electron coupling constant and discuss herein a potential new mechanism of superconductivity based on electron-electron interaction renormalization via the plasmon oscillating electric field. We also briefly discuss possible photoinduced $\epsilon$ near zero conditions.