RUS  ENG
Full version
JOURNALS // Nanosystems: Physics, Chemistry, Mathematics // Archive

Nanosystems: Physics, Chemistry, Mathematics, 2020 Volume 11, Issue 1, Pages 65–77 (Mi nano499)

This article is cited in 2 papers

PHYSICS

Fully self-consistent calculations of magnetic structure within non-collinear Alexander–Anderson model

A. V. Ivanovabc, P. F. Bessarabdcb, H. Jónssonebc, V. M. Uzdind

a Saint Petersburg State University, 199034, Saint Petersburg, Russia
b Faculty of Physical Sciences, U. of Iceland, 107 Reykjavík, Iceland
c Science Institute, U. of Iceland, 107 Reykjavík, Iceland
d ITMO University, 197101 Saint Petersburg, Russia
e Department of Applied Physics, Aalto University, FI-00076 Espoo, Finland

Abstract: An implementation of the non-collinear Alexander-Anderson model for itinerant electrons in magnetic systems is presented where self-consistency is reached for specified directions of the magnetic moments. This is achieved by means of Lagrange multipliers and a variational principle for determining the transverse and longitudinal components of the magnetic moments as well as the average number of d-electrons using direct optimisation. Various optimisation algorithms are compared and the limited memory Broyden–Fletcher–Goldfarb–Shanno algorithm is found to give the best performance. An application to antiferromagnetic Cr crystal is presented where spin-dynamics and curvature of the energy surface are calculated to compare results obtained with and without the constraints on the orientation of the magnetic moments.

Keywords: itinerant magnetism, Alexander–Anderson model, non-stationary configurations, constraints.

PACS: 05.20.Dd,75.10.-b

Received: 10.02.2020

Language: English

DOI: 10.17586/2220-8054-2020-11-1-65-77



Bibliographic databases:


© Steklov Math. Inst. of RAS, 2024