Magnetization Curves of Antiferromagnetic Heisenberg Spin-1/2 Ladders

TL;DR

This paper investigates the magnetization behavior of spin-1/2 Heisenberg ladders, revealing the existence of magnetization plateaux at specific rational fractions, especially in three-leg ladders, using multiple theoretical and numerical methods.

Contribution

It demonstrates the presence of magnetization plateaux at rational fractions in three-leg Heisenberg ladders, combining strong-coupling expansions, numerical diagonalization, and bosonization techniques.

Findings

Magnetization plateaux occur at specific rational fractions.

Plateaux at one-third saturation are confirmed in three-leg ladders.

Multiple methods corroborate the existence of these plateaux.

Abstract

Magnetization processes of spin-1/2 Heisenberg ladders are studied using strong-coupling expansions, numerical diagonalization of finite systems and a bosonization approach. We find that the magnetization exhibits plateaux as a function of the applied field at certain rational fractions of the saturation value. Our main focus are ladders with 3 legs where plateaux with magnetization one third of the saturation value are shown to exist.