Physics 250-06 “Advanced Electronic Structure”

Lecture 7.2. Calculations of Magnetic Interactions

Contents:

1. Non-collinear SDFT.

2. Applications to Magnetic Anisotropy Problem

3. Spin Spirals and Frozen Magnon Method, Curie Temperatures

3. Magnetic Force Theorem and Exchange Constants

4. Extensions for Strongly Correlated Systems

5. Recent Applications to Mott Insulators

Non-Collinear SDFT.

Magnetic Anisotropy Problem in Fe, Ni: Problems with LDA

Magnetic Anisotropy Energy in Fe and Ni.

Spin Spirals and Frozen Magnon Method.

Spin Spirals and Frozen Magnon Method.(Sandrztzky, 1986)

Relationship to Heisenberg Hamiltonian

Calculated Spin Spirals for Fe, Co, Ni

Calculations of Magnon Dispersions.

Frozen Magnons for Fe.

Frozen Magnons for Co.

Frozen Magnons for Ni.

Extracted Exchange Constants for Fe.

Magnetization vs Temperature for Fe.

Calculated Curie Temperatures for Fe, Co, Ni.

Magnetic Force Theorem. (Lichtenstein, 1986)

Expressions for Exchange Constants.

Goldstone Theorem.

Goldstone Theorem.

Goldstone Theorem.

Goldstone Theorem.

Spin Wave Spectra from Magnetic Force Theorem.(Antropov, 2002)

Low Frequency Parts of Spin Waves Spectra.

Extensions for Strongly Correlated Systems.

Exchange Constants for Strongly Correlated Systems.

Spin Waves in NiO.

Calculated Neel Temperatures in Transition Metal Oxides.