Ordering in the pyrochlore antiferromagnet due to Dzyaloshinsky-Moriya interactions

TL;DR

This paper investigates how Dzyaloshinsky-Moriya interactions influence the magnetic ordering in pyrochlore antiferromagnets, revealing a phase transition to long-range order at low temperatures through simulations and symmetry analysis.

Contribution

It demonstrates that Dzyaloshinsky-Moriya interactions induce a phase transition to magnetic order in pyrochlore antiferromagnets, providing explicit magnetic structures based on symmetry considerations.

Findings

DMI causes a phase transition to long-range order at low temperatures.

Ordered magnetic structures depend on the symmetry of DMI.

DMI significantly alters low-temperature magnetic behavior.

Abstract

The Heisenberg nearest neighbour antiferromagnet on the pyrochlore (3D) lattice is highly frustrated and does not order at low temperature where spin-spin correlations remain short ranged. Dzyaloshinsky-Moriya interactions (DMI) may be present in pyrochlore compounds as is shown, and the consequences of such interactions on the magnetic properties are investigated through mean field approximation and monte carlo simulations. It is found that DMI (if present) tremendously change the low temperature behaviour of the system. At a temperature of the order of the DMI a phase transition to a long range ordered state takes place. The ordered magnetic structures are explicited for the different possible DMI which are introduced on the basis of symmetry arguments. The relevance of such a scenario for pyrochlore compounds in which an ordered magnetic structure is observed experimentally is dicussed.