Abstract

Free-moving polarons are investigated in the framework of new one-electron model of conjugated polymers. It is shown that on a dimerized lattice there exist free (in the absence of an external force like an electric field) stationary polarons, both subsonic and supersonic. Subsonic free polarons are observed in the velocity range from 0 to the speed of sound. Supersonic free polarons are observed in a limited range of velocities. There is a range of forbidden velocities between subsonic and supersonic free polarons. An analytical expression for the free polaron shape at different velocities is derived and confirmed in molecular dynamics simulations. The dynamics of subsonic and supersonic polarons in an electric field is different. It is shown that the subsonic polaron motion is not stationary and the velocity oscillations are associated with the periodic emission of tensile impulses in front of the polaron, taking away the energy received from the electric field. The supersonic polaron motion is stationary and the energy gained from the electric field is permanently transformed into oscillations behind the polaron.

Graphical abstract

中文翻译：

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聚乙炔一电子模型中的亚音速和超音速极化子

摘要

在共轭聚合物的新单电子模型的框架内研究了自由移动的极化子。结果表明，在二聚晶格上，存在着亚音速和超音速的自由（在没有电场等外力的情况下）静止极化子。在从0到声速的速度范围内观察到亚音速自由极化子。在有限的速度范围内观察到超音速自由极化子。亚音速和超音速自由极化子之间存在一系列禁止的速度。推导了在不同速度下自由极化子形状的解析表达式，并在分子动力学模拟中得到了证实。电场中亚音速和超音速极化子的动力学是不同的。结果表明，亚音速极化子的运动不是平稳的，速度振荡与极化子前面周期性发出的拉伸脉冲有关，从而带走了从电场中接收到的能量。超音速极化子运动是固定的，从电场中获得的能量将永久性地转换为极化子后面的振荡。

图形概要