Discommensurational and Inhomogeneous States Induced by a Strong Magnetic Field in Low-Dimensional Antiferromagnets

TL;DR

This paper explores how strong magnetic fields induce complex discommensurational and inhomogeneous ground states in low-dimensional antiferromagnets, especially in spin ladder systems with different surface terminations.

Contribution

It identifies and characterizes various surface-induced phases and phase transitions in anisotropic antiferromagnetic systems under strong magnetic fields.

Findings

Surface spin flop phase in compensated systems

Discommensurational phase in non-compensated systems

First and second order phase transitions with a tricritical point

Abstract

Anisotropic antiferromagnetic systems of dimensionality greater than one in an external field are shown to exhibit a complicated array of ground states depending on the spin structure of the surface. The simplest structure that exhibits these effects is the spin ladder with the surface being the ladder end, which can be either compensated or non-compensated spins. The structure with the compensated end has a surface spin flop phase, the non-compensated end has a discommensurational phase, and the transition to these phases can be either first or second order with a tricritical point.