On the Novel Superfluidity in the Second Layer of $^4$He on Graphite
Other Condensed Matter
2026-01-12 v1
Abstract
Evidence for a new type of superfluid phase in second-layer He on graphite has been obtained from simultaneous measurements of torsional-oscillator response and heat-capacity on exactly the same sample down to 30 mK, which resolve substrate-related uncertainties in the previous studies. The new phase hosts both superfluidity and enhanced viscoelasticity, and is stable over a finite density interval, strongly supporting the proposed superfluid liquid-crystal hypothesis. A random-Josephson-network analysis shows that the widely reported log- dependence of the superfluid density is likely due to substrate imperfections.
Keywords
Cite
@article{arxiv.2601.05719,
title = {On the Novel Superfluidity in the Second Layer of $^4$He on Graphite},
author = {Jun Usami and Hiroshi Fukuyama},
journal= {arXiv preprint arXiv:2601.05719},
year = {2026}
}
Comments
Manuscript combined with Supplementary Materials; 15 pages, 12 figures