On the 'Supersolid' Response of the Second Layer of [Formula: see text] on Graphite

J Nyéki; A Phillis; B Cowan; J Saunders

doi:10.1007/s10909-017-1779-x

On the 'Supersolid' Response of the Second Layer of $^{4} He$ on Graphite

J Low Temp Phys. 2017;187(5):475-481. doi: 10.1007/s10909-017-1779-x. Epub 2017 Apr 27.

Authors

J Nyéki¹, A Phillis¹, B Cowan¹, J Saunders¹

Affiliation

¹ Department of Physics, Royal Holloway University of London, Egham, Surrey, TW20 0EX UK.

Abstract

Recent torsional oscillator measurements on the second layer of $^{4} He$ adsorbed on graphite have identified an anomalous superfluid response over a coverage range near third-layer promotion, with four distinct coverage regimes. Here, we present details of the superfluid response in the coverage regime immediately below third-layer promotion. A scaling analysis of the inferred superfluid fraction shows the characteristic temperature governing the superfluid response to decrease, approaching zero near the coverage at which simulations predict the second layer to form a conventional incommensurate solid.

Keywords: Film; Superfluid Helium-4; Supersolid.