Dynamics of coherences in the interacting double-dot Aharonov-Bohm interferometer: Exact numerical simulations

TL;DR

This paper investigates the real-time electron coherence dynamics in a double quantum dot Aharonov-Bohm interferometer, using exact numerical simulations and master equations to understand the effects of electron interactions.

Contribution

It extends a numerically exact path integral method to study coherence in interacting double-dot systems and compares results across different interaction regimes.

Findings

Coherence dynamics are preserved under weak-to-intermediate interactions.

In the Coulomb blockade limit, coherence behavior deviates significantly.

Steady-state coherence values differ between interaction regimes.

Abstract

We study the real time dynamics of electron coherence in a double quantum dot two-terminal Aharonov-Bohm geometry, taking into account repulsion effects between the dots' electrons. The system is simulated by extending a numerically exact path integral method, suitable for treating transport and dissipation in biased impurity models [Phys. Rev. B 82, 205323 (2010)]. Numerical simulations at finite interaction strength are supported by master equation calculations in two other limits: assuming non-interacting electrons, and working in the Coulomb blockade regime. Focusing on the intrinsic coherence dynamics between the double-dot states, we find that its temporal characteristics are preserved under weak-to-intermediate inter-dot Coulomb interaction. In contrast, in the Coulomb blockade limit, a master equation calculation predicts coherence dynamics and a steady-state value which notably deviate from the finite interaction case.