Mesoscopic behavior of the transmission phase through confined correlated electronic systems

TL;DR

This paper studies how electronic correlations affect the transmission phase in quantum dots, revealing that many experimentally observed features are better explained by one-particle wave-function correlations rather than many-particle interactions.

Contribution

The study demonstrates that electronic correlations alone cannot account for universal phase lapse behavior, supporting the relevance of chaotic ballistic dot models with wave-function correlations.

Findings

Electronic correlations influence transmission zeros and phase lapses.

Interaction effects do not reproduce universal phase behavior.

Chaotic ballistic dot models better explain experimental observations.

Abstract

We investigate the effect of electronic correlations on the transmission phase of quantum coherent scatterers, considering quantum dots in the Coulomb blockade regime connected to two single-channel leads. We focus on transmission zeros and the associated \pi-phase lapses that have been observed in interferometric experiments. We numerically explore two types of models for quantum dots: (i) lattice models with up to eight sites, and (ii) resonant level models with up to six levels. We identify different regimes of parameters where the presence of electronic correlations is responsible for the increase or the decrease of the number of transmission zeros vs. electrochemical potential on the dot. However, we show that interaction effects cannot reproduce the universal behavior of alternating resonances and phase lapses, experimentally observed in many-electron Coulomb blockaded dots. Our numerical results strongly suggest that the main experimentally observed features are captured by the theory for chaotic ballistic dots of Molina et al., [Phys. Rev. Lett. 108, 076803 (2012)] incorporating one-particle wave-function correlations but ignoring many-particle electronic correlations.