Charged bosons made of fermions in a solid state system without Cooper pairing

TL;DR

This paper presents experimental evidence for charged boson states formed by fermions in a solid state system without the need for Cooper pairing, supported by theoretical calculations and spectral measurements.

Contribution

It introduces a new type of charged boson complex in solid systems, demonstrating their stability and spectral signatures without relying on Cooper pairing mechanisms.

Findings

Spectral line observed at predicted energy in bilayer systems

Charged boson states depend on proximity to a metal layer

Potential implications for room temperature superconductivity

Abstract

We report experimental evidence for charged boson states in a solid without Cooper pairing, based on attaching two free carriers to an exciton in a semiconducting system. Theoretical calculations show that this type of complex is stable in bilayer systems next to a parallel metal layer. Our experimental measurements on structures made using two different materials show a new spectral line at the predicted energy, if and only if all the required conditions for this complex are fulfilled, including a parallel metal layer that significantly screens the repulsive interaction between the like-charge carriers, and with the predicted dependence on the distance to the metal layer. This suggests a new path for pursuing room temperature superconductivity without Cooper pairing.