# Third Harmonics and Defects in Modulated Phases of Structural Quantum Order-Disorder Systems

## TL;DR

This paper investigates how defects acting as random fields affect modulated phases in order-disorder systems, revealing that such defects can suppress third harmonics of the ground state modulation under certain conditions.

## Contribution

It demonstrates the impact of defects as random fields on the modulation harmonics in structural quantum order-disorder systems, highlighting a suppression mechanism.

## Key findings

- Defects can suppress third harmonics in modulated phases.
- Random fields influence the stability of ground state modulations.
- Suppression occurs under specific defect conditions.

## Abstract

Influences of defects generating random fields on modulated phases in materials with the order-disorder type of phase transition are studied. It is shown that under appropriate conditions third harmonics of the ground state modulation may be suppressed by these defects.