Superfluidity of zero-point vacancies in two-dimensional solid helium-4

为了研究石墨上4^He二维注册相的新型超流动性和玻色子量子晶体中的零点空位，利用扭转振子方法研究了在Grafoil上吸附的4^He薄膜的面密度依赖性和非经典转动惯量（NCRI）临界速度。我得到了2D 4He的相图，发现一个有限的NCRI只出现在注册相附近。

In order to investigate the novel superfluidity of the two-dimensional (2D) registered phase of 4^He on graphite and zero-point vacancies in bosonic quantum crystals, areal density dependence and critical velocity of non-classical rotational inertia (NCRI) in 4He films adsorbed on Grafoil were performed by a torsional oscillator method. I obtained the phase diagram of 2D 4He and discovered a finite NCRI appeared in only vicinity of the registered phase.