Magnetization plateaux in dimerized spin ladder arrays

TL;DR

This paper explores the complex magnetization plateaux in dimerized spin ladder systems, revealing unusual phases and their potential relevance to real materials like NH_4CuCl_3 through analytical and numerical methods.

Contribution

It introduces a detailed analysis of magnetization plateaux in dimerized spin ladders using bosonization and Lanczos techniques, highlighting novel phases and behaviors.

Findings

Identification of unusual magnetization plateaux.

Existence of massive and massless phases.

Relevance to experimental compound NH_4CuCl_3.

Abstract

We investigate the ground state magnetization plateaux appearing in spin 1/2 two-leg ladders built up from dimerized antiferromagnetic Heisenberg chains and dimerized zig-zag interchain couplings. Using both Abelian bosonization and Lanczos methods we find that the system yields rather unusual plateaux and exhibits massive and massless phases for specific choices or ``tuning'' of exchange interactions. The relevance of this behavior in the study of NH_4CuCl_3 is discussed.