Environment-assisted quantum transport and trapping in dimers

TL;DR

This paper investigates how an external environment influences excitation trapping in a quantum dimer system, revealing optimal environmental conditions that can accelerate decay times within specific intervals.

Contribution

It introduces a detailed analysis of environment-assisted quantum transport and trapping in dimers using a Lindblad master equation, highlighting optimal environmental couplings for faster decay.

Findings

Optimal environmental coupling enhances decay rates.

Certain lifetimes can be decreased with environmental effects.

Decays are not always improved by environmental interactions.

Abstract

We study the dynamics and trapping of excitations for a dimer with an energy off-set $\Delta$ coupled to an external environment. Using a Lindblad quantum master equation approach, we calculate the survival probability $\Pi(t)$ of the excitation and define different lifetimes $\tau_s$ of the excitation, corresponding to the duration of the decay of $\Pi(t)$ in between two predefined values. We show that it is not possible to always enhance the overall decay to the trap. However, it is possible, even for not too small environmental couplings and for values of $\Delta$ of the order ${\cal O}(1)$, to decrease certain lifetimes $\tau_s$, leading to faster decay of $\Pi(t)$ in these time intervals: There is an optimal environmental coupling, leading to a maximal decay for fixed $\Delta$.