Shear Modulus in Viscoelastic Solid 4He
Shear Modulus in Viscoelastic Solid 4He
复制标题
粘弹性固体 4He 中的剪切模量
DOI：
10.1007/s10909-010-0322-0
复制
发表时间：
2010
影响因子：
2
通讯作者：
A. Balatsky
中科院分区：
文献类型：
--
作者：
Jung;M. Graf;A. Balatsky
固体4 He的复剪切模量在扭转振子周期变化的同一温度区表现出异常。我们建议，所观察到的硬化的剪切模量随着温度的降低，可以很好地描述由固体4 He内的玻璃组分的响应。由于玻璃是一种滞弹性材料，我们利用粘弹性的方法来描述其动力学。粘弹性组分具有随着温度降低而增加的松弛。由此得出的响应函数是相同的玻璃，时间延迟恢复反作用。通过推广的粘弹性方程的应力和应变的多相系统的成分，组成的补丁具有不同的阻尼和松弛性能，我们预测的剪切模量的大小和耗散峰的最大高度的最大变化是独立的施加的外部频率。相同的响应表达式允许我们计算剪切模量的振幅和耗散的温度依赖性。最后，我们证明了Vogel-Fulcher-Tammann（VFT）弛豫时间与现有的实验数据一致。
The complex shear modulus of solid 4He exhibits an anomaly in the same temperature region where torsion oscillators show a change in period. We propose that the observed stiffening of the shear modulus with decreasing temperature can be well described by the response of glassy components inside of solid 4He. Since glass is an anelastic material, we utilize the viscoelastic approach to describe its dynamics. The viscoelastic component possesses an increasing relaxation as temperature decreases. The response functions thus derived are identical to those obtained for a glassy, time-delayed restoring back-action. By generalizing the viscoelastic equations for stress and strain to a multiphase system of constituents, composed of patches with different damping and relaxation properties, we predict that the maximum change of the magnitude of the shear modulus and the maximum height of the dissipation peak are independent of an applied external frequency. The same response expressions allow us to calculate the temperature dependence of the shear modulus’ amplitude and dissipation. Finally, we demonstrate that a Vogel-Fulcher-Tammann (VFT) relaxation time is in agreement with available experimental data.