Looking back at superfluid helium

TL;DR

This paper reviews the historical development, key properties, and theoretical understanding of superfluid helium, focusing on phenomena like boiling, vortices, rotons, and the superfluid transition under pressure.

Contribution

It provides a comprehensive retrospective analysis of superfluid helium's properties and discusses the implications of strong interactions on its condensate and transition temperature.

Findings

Role of rotons and vortices in critical velocity

Pressure dependence of superfluid transition temperature

Existence of condensate in strongly interacting liquid

Abstract

A few years after the discovery of Bose Einstein condensation in several gases, it is interesting to look back at some properties of superfluid helium. After a short historical review, I comment shortly on boiling and evaporation, then on the role of rotons and vortices in the existence of a critical velocity in superfluid helium. I finally discuss the existence of a condensate in a liquid with strong interactions, and the pressure variation of its superfluid transition temperature.