Electron Pair Resonance in the Coulomb Blockade

TL;DR

This paper investigates how electron pairs, facilitated by Coulomb repulsion, influence cotunneling currents in quantum dots, revealing new resonance features within Coulomb blockade regions at high bias voltages.

Contribution

It introduces the concept of electron pair resonance in Coulomb blockade, showing how many-body effects lead to distinct ionization peaks in the current derivatives.

Findings

Electron pair transfer causes resonance peaks at specific bias voltages.

New structure predicted within Coulomb-blockade diamonds.

Results highlight many-body effects in quantum transport.

Abstract

We study many-body corrections to the cotunneling current via a localized state with energy $\epsilon_d$ at large bias voltages $V$. We show that the transfer of {\em electron pairs}, enabled by the Coulomb repulsion in the localized level, results in ionization resonance peaks in the third derivative of the current with respect to $V$, centered at $eV=\pm 2\epsilon_d/3$. Our results predict the existence of previously unnoticed structure within Coulomb-blockade diamonds.