$h/2e$--Oscillations for Correlated Electron Pairs in Disordered Mesoscopic Rings

TL;DR

This paper numerically investigates two interacting electrons in a disordered mesoscopic ring, revealing $h/2e$-periodic states with pairing effects, demonstrating interaction-assisted coherent pair propagation across the entire ring.

Contribution

First direct numerical evidence of interaction-assisted coherent pair propagation in disordered mesoscopic rings with $h/2e$ oscillations.

Findings

Identification of $h/2e$-periodic states with pairing effects

Observation of pair delocalization on the scale of the entire ring

Numerical calculation of the full spectrum of two interacting electrons

Abstract

The full spectrum of two interacting electrons in a disordered mesoscopic one--dimensional ring threaded by a magnetic flux is calculated numerically. For ring sizes far exceeding the one--particle localization length $L_1$ we find several $h/2e$--periodic states whose eigenfunctions exhibit a pairing effect. This represents the first direct observation of interaction--assisted coherent pair propagation, the pair being delocalized on the scale of the whole ring.