We carry out quantum simulations to study the physical properties of diamond-like amorphous carbon by coupling first-principles molecular dynamics with a quantum thermostat, and we analyze multiple samples representative of different defective sites present in the disordered network. We show that quantum vibronic coupling is critical in determining the electronic properties of the system, in particular its electronic and mobility gaps, while it has a moderate influence on the structural properties. We find that despite localized electronic states near the Fermi level, the quantum nature of the nuclear motion leads to a renormalization of the electronic gap surprisingly similar to that found in crystalline diamond. We also discuss the notable influence of nuclear quantum effects on band-like and variable-hopping mechanisms contributing to electrical conduction. Our calculations indicate that methods often used to evaluate electron–phonon coupling in ordered solids are inaccurate to study the electronic and transport properties of amorphous semiconductors composed of light atoms.

中文翻译：

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核量子效应对无定形碳电子性质的影响

我们进行量子模拟，通过将第一性原理分子动力学与量子恒温器相结合来研究类金刚石无定形碳的物理性质，并且我们分析了代表无序网络中存在的不同缺陷位点的多个样本。我们表明，量子电子振动耦合对于确定系统的电子特性至关重要，特别是其电子和迁移率间隙，同时它对结构特性具有适度的影响。我们发现，尽管费米能级附近存在局部电子态，但核运动的量子性质导致电子间隙的重整化，这与在结晶金刚石中发现的惊人地相似。我们还讨论了核量子效应对有助于导电的带状和可变跳跃机制的显着影响。我们的计算表明，通常用于评估有序固体中电子 - 声子耦合的方法对于研究由轻原子组成的非晶半导体的电子和传输特性是不准确的。