Frequency dependence and dissipation in the dynamics of solid helium.
Frequency dependence and dissipation in the dynamics of solid helium.
复制标题
固体氦动力学中的频率依赖性和耗散。
DOI：
10.1103/physrevlett.104.195301
复制
发表时间：
2010
影响因子：
8.6
通讯作者：
J. Beamish
中科院分区：
文献类型：
--
作者：
O. Syshchenko;J. Day;J. Beamish
扭振实验固体4He显示频率的变化，这表明质量去耦，但发病是广泛的，并伴有耗散峰。我们已经测量了弹性剪切模量在一个很宽的频率范围内，从0.5 Hz到8 kHz，并观察到类似的行为硬化和耗散峰。这些特征与无序系统中的热激活弛豫过程中的动态交叉而不是真正的相变相关联。如果存在到直流响应的过渡，例如，到超固态，它必须在55 mK以下发生。
Torsional oscillator experiments on solid 4He show frequency changes which suggest mass decoupling, but the onset is broad and is accompanied by a dissipation peak. We have measured the elastic shear modulus over a broad frequency range, from 0.5 Hz to 8 kHz, and observe similar behavior-stiffening and a dissipation peak. These features are associated with a dynamical crossover in a thermally activated relaxation process in a disordered system rather than a true phase transition. If there is a transition to a dc response, e.g., to a supersolid state, it must occur below 55 mK.