论文标题
玻璃中软模式的应变场
Strain field of soft modes in glasses
论文作者
论文摘要
分析了低频振动模式中心周围的应变场，用于具有1/r^10排斥性势能的数值创建的二进制玻璃。在五到二十个原子的不稳定内核之外，人们发现了与芯中弦运动相似的运动混合物，并且中心中的三个振荡弹性偶极子的应变场。与应变场相比，额外的外部弦运动对核心的稳定贡献更大，但是应变场在长距离上占主导地位，这与最近的数值发现一致。外部弦运动的小恢复力将其平均频率接近玻色峰。该二进制玻璃中软模式的平均创造能量约为冷冻温度下热能的2.5倍。将数值模式的软势参数缩放到金属玻璃，发现与低温下的隧道状态以及通过玻色子峰处的多余模式来测量声音吸收的定量一致。
The strain field surrounding the center of low frequency vibrational modes is analyzed for numerically created binary glasses with a 1/r^10 repulsive interatomic potential. Outside the unstable inner core of five to twenty atoms, one finds a mixture of a motion similar to the string motion in the core with the strain field of three oscillating elastic dipoles in the center. The additional outside string motion contributes more to the stabilization of the core than the strain field, but the strain field dominates at long distances, in agreement with recent numerical findings. The small restoring force of the outside string motion places its average frequency close to the boson peak. The average creation energy of a soft mode in this binary glass is about 2.5 times the thermal energy at the freezing temperature. Scaling the soft potential parameters of the numerical modes to metallic glasses, one finds quantitative agreement with measurements of the sound absorption by tunneling states at low temperatures and by the excess modes at the boson peak.
