Susceptibility and Dzyaloshinskii-Moriya interaction in the Haldane gap compound NENP

TL;DR

This paper investigates the magnetic properties of the Haldane gap compound NENP, highlighting the role of Dzyaloshinskii-Moriya interaction in explaining various experimental anomalies.

Contribution

It proposes that considering Dzyaloshinskii-Moriya interaction is essential for a consistent understanding of NENP's magnetic behavior.

Findings

Anomalous low-temperature susceptibility observed.

Dzyaloshinskii-Moriya interaction explains experimental anomalies.

Reconciliation of multiple experimental data sets achieved.

Abstract

The Haldane gap material NENP exhibits anomalies in its Knight shift, far infrared absorption and field-dependent gaps, which have been explained using the staggered $g$-tensor that occurs due to the low crystal symmetry. We point out that the low-temperature susceptibility is also anomalous and that a consistent interpretation of all data may require consideration of the Dzyaloshinskii-Moriya interaction.