Multiple Diffusion-Freezing Mechanisms in Molecular-Hydrogen Films
Multiple Diffusion-Freezing Mechanisms in Molecular-Hydrogen Films
复制标题
氢分子薄膜中的多重扩散冷冻机制
DOI：
10.1103/physrevlett.123.245301
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发表时间：
2019
影响因子：
8.6
通讯作者：
and K. Shirahama
中科院分区：
文献类型：
--
作者：
T. Makiuchi;K. Yamashita;M. Tagai;Y. Nago;and K. Shirahama
分子氢是新型玻色子和费米子超流体的一个令人着迷的候选者。本文用弹性测量方法研究了吸附在玻璃衬底上的HD、HD和HD薄膜的扩散动力学。弹性表现出多个异常远低于体三相点温度。它们是由于三种不同的扩散机制的admolecules和他们的“冻结”成一个本地化的状态：经典的热扩散的空缺，量子隧道的空缺，和扩散的分子在最上层的表面。表面扩散是积极的，低至1 K，低于该分子成为本地化。这表明氢膜的表面层处于量子相变到超流态的边缘。
Molecular hydrogen is a fascinating candidate for novel bosonic and fermionic superfluids. We have studied diffusion dynamics of thin films of, HD, andadsorbed on a glass substrate by measurements of elasticity. The elasticity shows multiple anomalies well below the bulk triple point temperature. They are attributed to three different diffusion mechanisms of admolecules and their “freezing” into a localized state: classical thermal diffusion of vacancies, quantum tunneling of vacancies, and diffusion of molecules in the uppermost surface. The surface diffusion is active down to 1 K, below which the molecules become localized. This suggests that the surface layer of hydrogen films is on the verge of quantum phase transition to a superfluid state.