论文标题
无定形硅的内部机械耗散机制
Internal mechanical dissipation mechanisms in amorphous silicon
论文作者
论文摘要
使用激活 - 释放技术，我们在非晶硅（A-SI）模型中搜索两级系统（TLSS）。 TLS是与内部机械耗散有关的机制，代表了最大的重力波探测器最敏感的频率范围内的噪声主要来源，也代表了许多量子计算机中的主要脱碳的主要来源之一。我们表明，在A-SI中，大多数感兴趣的TLSS分为两个主要类别：债券缺失跳跃，邻居交换拓扑缺陷和Wooten-Winer-Winer-Wiare-Weaire债券交换。这些类别的分布在很大程度上取决于A-SI的准备时间表。我们使用结果来计算无定形硅的机械损耗，导致室温下的损耗角度为0.001，在某些配置中，在150 K时降至0.0001。我们的建模结果表明，多个类别的事件可能导致无序材料中与实验相关的TLSS，因此可能需要多种衰减策略来减少其影响。
Using the Activation-Relaxation Technique-nouveau, we search for two-level systems (TLSs) in models of amorphous silicon (a-Si). The TLSs are mechanisms related to internal mechanical dissipation and represent the main source of noise in the most sensitive frequency range of the largest gravitational wave detectors as well as one of the main sources of decoherence in many quantum computers. We show that in a-Si, the majority of the TLSs of interest fall into two main categories: bond-defect hopping where neighbors exchange a topological defect and the Wooten-Winer-Weaire bond exchange. The distribution of these categories depends heavily on the preparation schedule of the a-Si. We use our results to compute the mechanical loss in amorphous silicon, leading to a loss angle of 0.001 at room temperature, decreasing to 0.0001 at 150 K in some configurations. Our modeling results indicate that multiple classes of events can cause experimentally-relevant TLSs in disordered materials and, therefore, multiple attenuation strategies might be needed to reduce their impact.
