This title appears in the Scientific Report :
2014
Please use the identifier:
http://dx.doi.org/10.1007/128_2013_518 in citations.
Spin Excitations in Solids from Many-Body Perturbation Theory
Spin Excitations in Solids from Many-Body Perturbation Theory
Collective spin excitations form a fundamental class of excitations in magnetic materials. As their energy reaches down to only a few meV, they are present at all temperatures and substantially influence the properties of magnetic systems. To study the spin excitations in solids from first principle...
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Personal Name(s): | Friedrich, Christoph (Corresponding Author) |
---|---|
Şaşıoğlu, Ersoy / Müller, Mathias Christian Thomas David / Schindlmayr, Arno / Blügel, Stefan | |
Contributing Institute: |
Quanten-Theorie der Materialien; IAS-1 Quanten-Theorie der Materialien; PGI-1 |
Published in: | 2014 |
Published in: |
First Principles Approaches to Spectroscopic Properties of Complex Materials |
Imprint: |
Berlin, Heidelberg
Springer Berlin Heidelberg
2014
|
Physical Description: |
259 - 301 |
ISBN: |
978-3-642-55068-3 (electronic) 978-3-642-55067-6 (print) |
DOI: |
10.1007/128_2013_518 |
Document Type: |
Contribution to a book |
Research Program: |
Spin-based and quantum information |
Series Title: |
Topics in Current Chemistry
347 |
Publikationsportal JuSER |
Collective spin excitations form a fundamental class of excitations in magnetic materials. As their energy reaches down to only a few meV, they are present at all temperatures and substantially influence the properties of magnetic systems. To study the spin excitations in solids from first principles, we have developed a computational scheme based on many-body perturbation theory within the full-potential linearized augmented plane-wave (FLAPW) method. The main quantity of interest is the dynamical transverse spin susceptibility or magnetic response function, from which magnetic excitations, including single-particle spin-flip Stoner excitations and collective spin-wave modes as well as their lifetimes, can be obtained. In order to describe spin waves we include appropriate vertex corrections in the form of a multiple-scattering T matrix, which describes the coupling of electrons and holes with different spins. The electron–hole interaction incorporates the screening of the many-body system within the random-phase approximation. To reduce the numerical cost in evaluating the four-point T matrix, we exploit a transformation to maximally localized Wannier functions that takes advantage of the short spatial range of electronic correlation in the partially filled d or f orbitals of magnetic materials. The theory and the implementation are discussed in detail. In particular, we show how the magnetic response function can be evaluated for arbitrary k points. This enables the calculation of smooth dispersion curves, allowing one to study fine details in the k dependence of the spin-wave spectra. We also demonstrate how spatial and time-reversal symmetry can be exploited to accelerate substantially the computation of the four-point quantities. As an illustration, we present spin-wave spectra and dispersions for the elementary ferromagnet bcc Fe, B2-type tetragonal FeCo, and CrO2 calculated with our scheme. The results are in good agreement with available experimental data. |