Quantum Critical Phenomena of 4He in Nanoporous Media

TL;DR

This paper investigates the quantum critical behavior of superfluid helium-4 in nanoporous Gelsil glass, highlighting the role of quantum fluctuations and universality class, and demonstrating good agreement with experimental data.

Contribution

It identifies the quantum critical phenomena of 4He in Gelsil as belonging to the 4D XY universality class, emphasizing the importance of quantum fluctuations due to small pore sizes.

Findings

Quantum fluctuations are significant at studied temperatures.

The system exhibits 4D XY universality class behavior.

Scaling analysis matches experimental observations.

Abstract

The superfluid transition in liquid 4He filled in Gelsil glass observed in recent experiments is discussed in the framework of quantum critical phenomena. We show that quantum fluctuations of phase are indeed important at the experimentally studied temperature range owing to the small pore size of Gelsil, in contrast to 4He filled in previously studied porous media such as Vycor glass. As a consequence of an effective particle-hole symmetry, the quantum critical phenomena of the system are described by the 4D XY universality class, except at very low temperatures. The simple scaling agrees with the experimental data remarkably well.