Superfluid density in quasi-one-dimensional systems
Superfluid density in quasi-one-dimensional systems
复制标题
准一维系统中的超流体密度
DOI：
10.1103/physrevb.83.174515
复制
发表时间：
2011
影响因子：
3.7
通讯作者：
D. Hirashima
中科院分区：
文献类型：
--
作者：
A. Kotani;K. Yamashita;D. Hirashima
结合最近的准一维液态氦实验，用蒙特卡罗方法计算了准一维经典模型中的螺旋度模数。与超流体密度密切相关的螺旋度模数受相滑移的影响较大。然而，在动力学实验中不一定要探讨相滑移的影响。提出了两种不受相滑移影响的螺旋度模数的计算方法：一种是使用禁止相滑移的边界条件，另一种是将蒙特卡罗采样限制在没有相滑移的样品上。结果表明，即使在一维极限条件下，螺旋度模数也能在Kosterlitz-Thouless转变温度(薄膜中)或体相变温度(棒中)这样的高温下存活。在此基础上，指出了有膜和有条形两种情况在热涡激发数上的显著差异。讨论了本结果与最近有关准一维氦超流的实验结果的相关性。
The helicity modulus in a quasi-one-dimensional classicalmodel is calculated with the Monte Carlo method in connection with recent experiments on liquid He in quasi-one-dimension. The helicity modulus, which is closely related to superfluid density, is strongly reduced by phase slippage. However, the effect of phase slippage is not necessarily probed in a dynamical experiment. Two methods to calculate the helicity modulus that are not affected by phase slippage are proposed: One is to use a boundary condition that prohibits phase slippage and the other is to restrict the Monte Carlo sampling to samples without phase slippage. It is then found that the helicity modulus can survive at such a high temperature as the Kosterlitz-Thouless transition temperature (in films) or the bulk transition temperature (in bars) even in the one-dimensional limit. A remarkable difference in the number of thermal vortex excitations between the cases with a film and a bar is then pointed out. The relevance of the present results to recent experiments on the superfluidity of quasi-one-dimensional He is discussed.