# Monte Carlo modeling the phase diagram of magnets with the Dzyaloshinskii - Moriya interaction

## TL;DR

This study employs Monte Carlo simulations to explore how pressure-induced changes in exchange and Dzyaloshinskii-Moriya interactions influence phase transitions in helical magnets, providing insights into their high-pressure phase diagrams.

## Contribution

It introduces a Monte Carlo modeling approach to analyze the pressure dependence of phase transitions in helical magnets considering Dzyaloshinskii-Moriya interactions.

## Key findings

- Phase transition depends critically on the D/J ratio.
- Pressure alters J and D, affecting transition temperature and fluctuation region.
- Model results are relevant to MnSi and Cu2OSeO3 high-pressure behavior.

## Abstract

We use classical Monte Carlo calculations to model the high-pressure behavior of the phase transition in the helical magnets. We vary values of the exchange interaction constant J and the Dzyaloshinskii-Moriya interaction constant D, which is equivalent to changing spin-spin distances, as occurs in real systems under pressure. The system under study is self-similar at D/ J = constant, and its properties are defined by the single variable J / T , where T is temperature. The existence of the first order phase transition critically depends on the ratio D / J. A variation of J strongly affects the phase transition temperature and width of the fluctuation region (the hump) as follows from the system self-similarity. The high-pressure behavior of the spin system depends on the evolution of the interaction constants J and D on compression. Our calculations are relevant to the high pressure phase diagrams of helical magnets MnSi and Cu2OSeO3.