Quantum phase transitions in antiferromagnets and superfluids

TL;DR

This paper reviews the dynamic and transport properties of low-dimensional systems near quantum phase transitions, connecting theoretical models with experimental findings in various quantum materials.

Contribution

It provides a comprehensive overview of quantum phase transitions in low-dimensional systems, integrating recent large N computations with experimental data.

Findings

Experimental results on spin-ladder compounds and antiferromagnets analyzed.

Large N computations suggest a unified scenario for quantum phases in high-Tc superconductors.

Connections established between theory and diverse experimental observations.

Abstract

We present a general introduction to the non-zero temperature dynamic and transport properties of low-dimensional systems near a quantum phase transition. Basic results are reviewed in the context of experiments on the spin-ladder compounds, insulating two-dimensional antiferromagnets, and double-layer quantum Hall systems. Recent large N computations on an extended t-J model (cond-mat/9906104) motivate a global scenario of the quantum phases and transitions in the high temperature superconductors, and connections are made to numerous experiments.