We have measured the heat capacity of 4He films adsorbed in Vycor glass for temperatures down to 10 mK and coverages close to the critical coverage for the onset of superfluidity at T=0. The data show that the critical coverage corresponds to a mobility edge in the chemical potential, below which the 4He film is an insulator with a gap. We find no evidence for the existence of a gapless Bose glass phase.
|Original language||English (US)|
|Number of pages||4|
|Journal||Physical Review Letters|
|State||Published - Jan 1 1995|