论文标题
在氩气镀上MCM-41纳米孔内氦4的尺寸降低
Dimensional Reduction of Helium-4 Inside Argon Plated MCM-41 Nanopores
论文作者
论文摘要
在低温下描述氦4的超流动波函数的Angstrom尺度相干性长度阻止了其在真正的一维几何形状中的制备。介孔有序的基于二氧化硅的结构（例如分子筛MCM-41）为物理限制提供了有前途的途径，但是可以化学合成的最小孔直径已被证明太大了，无法达到Quasi-niwdigensional二维极限。我们通过用单个，良好的AR气体层预先镀孔，然后用氦气填充毛孔，从而对此问题提出一种主动的纳米工程方法。通过实验吸附等温线和中子散射测量结果研究孔内的结构，与大规模量子蒙特卡洛模拟一致。结果表明，4He原子在MCM-41内经历的有效限制潜力的埃昂斯特罗姆（Angstrom）和开尔文（Kelvin）尺度可调节性，而AR层将限制介质的直径降低到一个固体层围绕一维量子液体的状态中。
The angstrom-scale coherence length describing the superfluid wavefunction of helium-4 at low temperatures has prevented its preparation in a truly one-dimensional geometry. Mesoporous ordered silica-based structures, such as the molecular sieve MCM-41, offer a promising avenue towards physical confinement, but the minimal pore diameters that can be chemically synthesized have proven to be too large to reach the quasi-one-dimensional limit. We present an active nano-engineering approach to this problem by pre-plating MCM-41 with a single, well controlled layer of Ar gas before filling the pores with helium. The structure inside the pore is investigated via experimental adsorption isotherms and neutron scattering measurements that are in agreement with large scale quantum Monte Carlo simulations. The results demonstrate angstrom and kelvin scale tunability of the effective confinement potential experienced by 4He atoms inside the MCM-41, with the Ar layer reducing the diameter of the confining media into a regime where a number of solid layers surround a one-dimensional quantum liquid.
