Superfluidity of dense 4He in vycor.
Superfluidity of dense 4He in vycor.
复制标题
vycor 中致密 4He 的超流动性。
DOI：
10.1103/physrevlett.95.185301
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发表时间：
2005
影响因子：
8.6
通讯作者：
D. Ceperley
中科院分区：
文献类型：
--
作者：
S. Khairallah;D. Ceperley
本文用路径积分蒙特卡罗方法计算了Vycor中4He模型的性质。我们发现，4He形成了一个独特的分层结构与高度本地化的第一层，无序的第二层与一些原子离域，并能够引起所观察到的超流响应，和更高的层几乎完美的晶体。一个3He原子的加入就足以通过阻止第二层中的交换来降低总的超流性。我们的结果与持久液层模型解释观测结果是一致的。这种模型可能是相关的大块固体4He的实验，如果有一个精细的晶界网络在这些系统。
We calculate properties of a model of 4He in Vycor using the path integral Monte Carlo method. We find that 4He forms a distinct layered structure with a highly localized first layer, a disordered second layer with some atoms delocalized and able to give rise to the observed superfluid response, and higher layers of nearly perfect crystals. The addition of a single 3He atom was enough to bring down the total superfluidity by blocking the exchange in the second layer. Our results are consistent with the persistent liquid-layer model to explain the observations. Such a model may be relevant to the experiments on bulk solid 4He, if there is a fine network of grain boundaries in those systems.