NMR relaxation in half-integer antiferromagnetic spin chains

TL;DR

This paper investigates nuclear magnetic resonance relaxation in half-integer antiferromagnetic spin chains at low temperatures, revealing universal behaviors driven by thermally-excited spinons and providing theoretical calculations of relaxation rates.

Contribution

It provides the first detailed theoretical analysis of NMR relaxation rates in half-integer antiferromagnetic spin chains at low temperatures, emphasizing the role of spinon dissipation.

Findings

Universal low-temperature dependence of relaxation rates $1/T_1$ and $1/T_{2G}$.

Dissipation from a gas of thermally-excited, overdamped spinons dominates relaxation.

Theoretical calculations match expected physical behaviors in these quantum spin systems.

Abstract

Nuclear relaxation in half-integer spin chains at low temperatures (T << J, the antiferromagnetic exchange constant) is dominated by dissipation from a gas of thermally-excited, overdamped, spinons. The universal low temperature dependence of the relaxation rates $1/T_1$ and $1/T_{2G}$ is computed.