Yachay Tech University, School of Physical Sciences and Nanotechnology, 100119 Urcuqui, Ecuador.
School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287-1604, USA and Ikerbasque Foundation and Donostia International Physics Center (DIPC), Manuel de Lardizabal Pasealekua 4, 20018 Donostia, Euskadi, Spain.
J Chem Phys. 2020 Oct 28;153(16):165102. doi: 10.1063/5.0023775.
We analyze the influence of electron-phonon (e-ph) interaction in a model for electron transfer (ET) processes in DNA in terms of the envelope function approach for spinless electrons. We are specifically concerned with the effect of e-ph interaction on the coherence of the ET process and how to model the interaction of DNA with phonon reservoirs of biological relevance. We assume that the electron bearing orbitals are half filled and derive the physics of e-ph coupling in the vicinity in reciprocal space. We find that at half filling, the acoustical modes are decoupled to ET at first order, while optical modes are predominant. The latter are associated with inter-strand vibrational modes in consistency with previous studies involving polaron models of ET. Coupling to acoustic modes depends on electron doping of DNA, while optical modes are always coupled within our model. Our results yield e-ph coupling consistent with estimates in the literature, and we conclude that large polarons are the main result of such e-ph interactions. This scenario will have strong consequences on decoherence of ET under physiological conditions due to relative isolation from thermal equilibration of the ET mechanism.
我们分析了电子-声子（e-ph）相互作用对 DNA 中电子转移（ET）过程的影响，方法是使用无自旋电子的包络函数方法。我们特别关注 e-ph 相互作用对 ET 过程相干性的影响，以及如何对 DNA 与生物相关的声子库的相互作用进行建模。我们假设承载电子的轨道是半满的，并在倒空间的附近推导 e-ph 耦合的物理性质。我们发现，在半满时，声学模式在一阶与 ET 解耦，而光学模式占主导地位。后者与以前涉及 ET 极化子模型的研究中一致，与链间振动模式相关。与声学模式的耦合取决于 DNA 的电子掺杂，而光学模式在我们的模型中总是耦合的。我们的结果得到了与文献估计一致的 e-ph 耦合，我们得出结论，大极化子是这种 e-ph 相互作用的主要结果。由于 ET 机制与热平衡的相对隔离，这种情况将对生理条件下 ET 的退相干产生强烈影响。
