We derive a new microscopic spin Hamiltonian for Rashba-coupled double exchange metals. The Hamiltonian consists of anisotropic interactions of the Dzyaloshinskii-Moriya (DM) and Kitaev form, in addition to the standard isotropic term. We validate the spin Hamiltonian by comparing results with those on the exact spin-fermion model, and present its phase diagram using large scale Monte Carlo simulations. In addition to ferromagnetic, planar spiral and flux states, the model hosts skyrmion crystal and classical spin-liquid states characterized, respectively, by multiple peaks and a diffuse ring pattern in the spin structure factor. The filamentary domain wall structures in the spin-liquid state are in remarkable agreement with experimental data on thin films of MnSi-type B20 metals and transition metals and their alloys.
@article{arxiv.2003.11245,
title = {New Microscopic Magnetic Hamiltonian for Exotic Spin Textures in Metals},
author = {Deepak S. Kathyat and Arnob Mukherjee and Sanjeev Kumar},
journal= {arXiv preprint arXiv:2003.11245},
year = {2020}
}
Comments
A sign mistake in the derivation is corrected in the 2nd version. Figures have been updated