Localization of Bose-Einstein Condensation and Disappearance of Superfluidity of Strongly Correlated Bose Fluid in a Confined Potential

TL;DR

This paper models a confined Bose fluid to explain the localization of Bose-Einstein condensation and loss of superfluidity observed in liquid helium-4 at high pressures, providing a quantitative criterion matching experiments.

Contribution

It introduces a new analytical criterion for the transition to a localized Bose-Einstein condensate phase in confined geometries.

Findings

Critical pressure for phase transition matches experimental data.

Localization of Bose-Einstein condensate occurs when its size is comparable to confinement scale.

Superfluidity disappears at the transition point.

Abstract

We develop a Bose fluid model in a confined potential to consider the new quantum phase due to the localization of Bose-Einstein condensation and disappearance of superfluidity which is recently observed in liquid 4He in porous glass at high pressures. A critical pressure of the transition to this phase can be defined by our new analytical criterion of supposing the size of localized Bose-Einstein condensate becomes comparable to the scale of confinement. The critical pressure is quantitatively consistent with observations without free parameters.