# Non-collinear spin-spiral phase for the uniform electron gas within Reduced-Density-Matrix-Functional Theory

## TL;DR

This paper investigates the stability of non-collinear spin-spiral density waves in the uniform electron gas using Reduced-Density-Matrix-Functional Theory, extending previous Hartree-Fock results by including correlation effects.

## Contribution

It provides a detailed numerical analysis of spin-spiral density waves within RDMFT and explores how correlations influence their instability, advancing understanding beyond Hartree-Fock approximation.

## Key findings

- Hartree-Fock predicts instability of paramagnetic state to density waves
- Correlations modify the spin-spiral density wave instability
- Numerical results demonstrate the impact of correlations on phase stability

## Abstract

The non-collinear spin-spiral density wave of the uniform electron gas is studied in the framework of Reduced-Density-Matrix-Functional Theory. For the Hartree-Fock approximation, which can be obtained as a limiting case of Reduced-Density-Matrix-Functional Theory, Overhauser showed a long time ago that the paramagnetic state of the electron gas is unstable with respect to the formation of charge or spin density waves. Here we not only present a detailed numerical investigation of the spin-spiral density wave in the Hartree-Fock approximation but also investigate the effects of correlations on the spin-spiral density wave instability by means of a recently proposed density-matrix functional.