A Study of the Superfluid Transition in Films Adsorbed to Rough Over a Large Temperature Range

作者：Wadleigh L R; Luhman D R^*

来源：Journal of Low Temperature Physics, 2014, 177(3-4): 178-192.

DOI：10.1007/s10909-014-1200-y

• Superfluid helium films
• Berezinskii-Kosterlitz-Thouless transition
• Disordered two dimensional systems

Rough two-dimensional substrates, such as thermally deposited , have been shown to modify the experimental signatures of the superfluid transition in adsorbed thin helium films. Previous experiments have investigated a series of increasingly rough surfaces over a limited temperature range and found that the features at the superfluid transition become less defined as substrate roughness is increased. In this work we study the superfluid transition in adsorbed helium films over a wide range of temperatures for a series of substrates. Our results show that as the transition temperature increases the abrupt jump in superfluid density at the transition becomes less distinct. The changing characteristics of the transition on a single substrate with temperature suggest that the reduced observability of the transition on rough substrates cannot be explained entirely by superfluid drag. We discuss several other possible scenarios which may be relevant to the helium films on .

• 出版日期2014-11