Surface-dominated finite size effects in nanoconfined superfluid helium
Mesoscale and Nanoscale Physics
2022-10-12 v2
Abstract
Superfluid He (He-II) is a widely studied model system for exploring finite-size effects in strongly confined geometries. Here, we study He-II confined in mm-scale channels of 25 and 50 nm height at high pressures using a nanofluidic Helmholtz resonator. We find that the superfluid density is measurably suppressed in the confined geometry from the transition temperature down to 0.6 K. Importantly, this suppression can be accounted for by roton-like thermal excitation with an energy gap of 5 K. We show that the surface-bound excitations lead to the previously unexplained lack of finite-size scaling of suppression of the superfluid density.
Keywords
Cite
@article{arxiv.2202.11725,
title = {Surface-dominated finite size effects in nanoconfined superfluid helium},
author = {E. Varga and C. Undershute and J. P. Davis},
journal= {arXiv preprint arXiv:2202.11725},
year = {2022}
}
Comments
Version 2: 14 pages (5 + 9 supplemental material; 3 + 10 figures). Accepted to Phys. Rev. Lett