Quantum Phase Transitions in 2d Quantum Liquids

TL;DR

This paper introduces the theory of continuous quantum phase transitions in 2D quantum liquids, emphasizing universality classes and their relevance to various condensed matter systems at zero temperature.

Contribution

It provides a pedagogical overview of quantum phase transitions in 2D systems, highlighting the role of universality classes with and without disorder.

Findings

Universality classes are central to understanding 2D quantum phase transitions.

Different condensed matter systems exhibit similar critical behavior.

Disorder influences the universality class of the transition.

Abstract

These lectures provide a pedagogical introduction to the theory of continuous quantum phase transitions. Various two-dimensional condensed matter systems, such as a superconducting film, a quantum Hall liquid, and an array of Josephson junctions, undergo such a phase transition at the absolute zero of temperature. The universality classes defined by repulsively interacting bosons with and without disorder are shown to play a central role in understanding these systems.