Influence of lattice distortions in classical spin systems

TL;DR

This paper explores how lattice distortions influence magnetization plateaus and phase transitions in a frustrated classical spin chain coupled to phonons, combining numerical and analytical methods.

Contribution

It demonstrates that moderate lattice coupling stabilizes a 1/3 magnetization plateau and characterizes the nature of the transition to saturation.

Findings

Lattice coupling stabilizes a 1/3 magnetization plateau.

Transition to saturation can be first or second order.

Lattice deformation occurs in the plateau phase.

Abstract

We investigate a simple model of a frustrated classical spin chain coupled to adiabatic phonons under an external magnetic field. A thorough study of the magnetization properties is carried out both numerically and analytically. We show that already a moderate coupling with the lattice can stabilize a plateau at 1/3 of the saturation and discuss the deformation of the underlying lattice in this phase. We also study the transition to saturation where either a first or second order transition can occur, depending on the couplings strength.