Spatially Modulated Superfluid State in Two-Dimensional $^4$He Films
Abstract
The second layer of He films adsorbed on a graphite substrate is an excellent experimental platform to study the interplay between superfluid and structural orders. Here, we report a rigid two-frequency torsional oscillator study on the second layer as a function of temperature and He atomic density. We find that the superfluid density is independent of frequency, which can be interpreted as unequivocal evidence of genuine superfluidity. The phase diagram established in this work reveals that a superfluid phase coexists with hexatic density-wave correlation and a registered solid phase. This suggests the second layer as a candidate for hosting two exotic quantum ground states: the spatially modulated superfluid and supersolid phases, resulting from the interplay between superfluid and structural orders.
Keywords
Cite
@article{arxiv.2108.06623,
title = {Spatially Modulated Superfluid State in Two-Dimensional $^4$He Films},
author = {Jaewon Choi and Alexey A. Zadorozhko and Jeakyung Choi and Eunseong Kim},
journal= {arXiv preprint arXiv:2108.06623},
year = {2021}
}
Comments
accepted in Phys. Rev. Lett. (7 pages, 4 figure, Supplemental Materials)