Weak localization, Aharonov-Bohm oscillations and decoherence in arrays of quantum dots

TL;DR

This paper presents a comprehensive theoretical framework combining multiple techniques to study how electron-electron interactions cause decoherence and affect quantum interference phenomena in various quantum dot arrays, aligning well with experimental data.

Contribution

It introduces a unified non-perturbative model that accounts for electron-electron interactions in different types of disordered conductors and quantum dots, explaining zero-temperature decoherence.

Findings

Electron decoherence time saturates at finite value as temperature approaches zero.

The universal formula for decoherence time matches experimental observations.

Electron-electron interactions are confirmed as a universal decoherence mechanism.

Abstract

Combining scattering matrix theory with non-linear $\sigma$-model and Keldysh technique we develop a unified theoretical approach enabling one to non-perturbatively study the effect of electron-electron interactions on weak localization and Aharonov-Bohm oscillations in arbitrary arrays of quantum dots. Our model embraces (i) weakly disordered conductors (ii) strongly disordered conductors and (iii) metallic quantum dots. In all these cases at $T \to 0$ the electron decoherence time is found to saturate to a finite value determined by the universal formula which agrees quantitatively with numerous experimental results. Our analysis provides overwhelming evidence in favor of electron-electron interactions as a universal mechanism for zero temperature electron decoherence in disordered conductors.