Introduction to the Modern Theory of Bose-Einstein Condensation, Superfluidity, and Superconductivity

TL;DR

This paper reviews the modern theoretical understanding of Bose-Einstein condensation, superfluidity, and superconductivity, highlighting thermodynamic principles, equations of motion, computer simulations, and comparisons with older theories.

Contribution

It provides a comprehensive overview of current theories, including new insights from computer simulations and critical analysis of traditional approaches.

Findings

Simulation of Lennard-Jones helium reproduces superfluid transition

Thermodynamic principles underpin superfluid flow

Comparison clarifies advances over older theories

Abstract

The modern theory of Bose-Einstein condensation, superfluidity, and superconductivity is reviewed. The thermodynamic principle for superfluid flow and the equation of motion for condensed bosons are given. Computer simulations of Lennard-Jones $^4$He give the $\lambda$-transition and the superfluid viscosity. The statistical mechanical theory of high-temperature superconductivity is presented. Critical comparison is made with older approaches, such as ground energy state condensation, irrotational superfluid flow, and the macroscopic wavefunction.