Tuning the Coherent Propagation of Organic Exciton-Polaritons through the Cavity Q-factor
arxiv(2023)
摘要
Transport of excitons in organic materials can be enhanced through polariton
formation when the interaction strength between these excitons and the confined
light modes of an optical resonator exceeds their decay rates. While the
polariton lifetime is determined by the Q(uality)-factor of the optical
resonator, the polariton group velocity is not. Instead, the latter is solely
determined by the polariton dispersion. Yet, experiments suggest that the
Q-factor also controls the polariton propagation velocity. To understand this
observation, we performed molecular dynamics simulations of Rhodamine
chromophores strongly coupled to Fabry-Pérot cavities with various Q-factors.
Our results suggest that propagation in the aforementioned experiments is
initially dominated by ballistic motion of upper polariton states at their
group velocities, which leads to a rapid expansion of the wavepacket. Cavity
decay in combination with non-adiabatic population transfer into dark states,
rapidly depletes these bright states, causing the wavepacket to contract.
However, because population transfer is reversible, propagation continues, but
as a diffusion process, at lower velocity. By controlling the lifetime of
bright states, the Q-factor determines the duration of the ballistic phase and
the diffusion coefficient in the diffusive regime. Thus, polariton propagation
in organic microcavities can be effectively tuned through the Q-factor.
更多查看译文
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要