Magnetization Jump in the Spin-1/2 XXZ Chain with Next-Nearest-Neighbour Coupling

TL;DR

This paper investigates the zero-temperature magnetization behavior of a one-dimensional spin-1/2 XXZ chain with next-nearest-neighbor coupling, revealing conditions for magnetization jumps and analyzing excitation spectra.

Contribution

It determines the boundary conditions for magnetization jumps in the XXZ chain with next-nearest-neighbor coupling and distinguishes cases based on the coupling strength.

Findings

Magnetization jumps occur in specific parameter regions.

Boundary of the jump region is explicitly determined.

Double minimum structure in excitation spectrum for alpha > 1/4.

Abstract

The zero-temperature magnetization process of a one-dimensional S=1/2 spin system with next-nearest-neighbour coupling alpha and anisotropy delta is studied. There is a region in the parameter space where the magnetization has a jump at certain external field. The boundary of this region is determined. The two cases are distinguished according as alpha<1/4 or alpha>1/4. In the latter case, the energy dispersion of the low-lying excitations exhibits a double minimum structure.