Environment-assisted quantum transport and trapping in dimers

Area of Science:

• Quantum dynamics
• Excited-state physics
• Open quantum systems

Background:

• Understanding excitation dynamics in molecular systems is crucial for energy transfer processes.
• The influence of environmental coupling on quantum systems can lead to complex behaviors like trapping and decay.
• Dimer systems serve as fundamental models for studying energy transfer and coherence.

Purpose of the Study:

• To investigate the dynamics and trapping of excitations in an energy-offset dimer coupled to an environment.
• To analyze the effect of environmental coupling strength and energy offset on excitation survival probability and lifetimes.
• To determine if and under what conditions excitation decay can be enhanced.

Main Methods:

• Utilized a Lindblad quantum master equation approach to model the open quantum system.
• Calculated the excitation survival probability, denoted as Π(t).
• Defined and analyzed excitation lifetimes, τ(s), based on specific decay intervals of Π(t).

Main Results:

• It is not always possible to enhance the overall excitation decay to the trap.
• For moderate environmental couplings and energy offsets (Δ of order O(1)), specific lifetimes τ(s) can be decreased.
• Faster decay within certain time intervals is achievable, indicating an optimal environmental coupling for maximal decay.

Conclusions:

• Environmental coupling offers a tunable parameter to control excitation dynamics in dimers.
• Optimal environmental coupling can lead to accelerated decay within specific time scales, even if overall decay is not improved.
• These findings have implications for controlling energy transfer and coherence in quantum systems.