Geometrical contributions to the exchange constants: Free electrons with spin-orbit interaction
Freimuth F, Bluegel S, Mokrousov Y (2017)
Publication Type: Journal article
Publication year: 2017
Journal
Book Volume: 95
Article Number: 184428
Journal Issue: 18
DOI: 10.1103/PhysRevB.95.184428
Abstract
Using thermal quantum field theory, we derive an expression for the exchange constant that resembles Fukuyama's formula for orbital magnetic susceptibility (OMS). Guided by this formal analogy between the exchange constant and OMS, we identify a contribution to the exchange constant that arises from the geometrical properties of the band structure in mixed phase space. We compute the exchange constants for free electrons and show that the geometrical contribution is generally important. Our formalism allows us to study the exchange constants in the presence of spin-orbit interaction. Thereby, we find sizable differences between the exchange constants of helical and cycloidal spin spirals. Furthermore, we discuss how to calculate the exchange constants based on a gauge-field approach in the case of the Rashba model with an additional exchange splitting, and we show that the exchange constants obtained from this gauge-field approach are in perfect agreement with those obtained from the quantum field theoretical method.
Involved external institutions
Germany (DE)How to cite
APA:
Freimuth, F., Bluegel, S., & Mokrousov, Y. (2017). Geometrical contributions to the exchange constants: Free electrons with spin-orbit interaction. Physical Review B, 95(18). https://doi.org/10.1103/PhysRevB.95.184428
MLA:
Freimuth, Frank, Stefan Bluegel, and Yuriy Mokrousov. "Geometrical contributions to the exchange constants: Free electrons with spin-orbit interaction." Physical Review B 95.18 (2017).
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