Trushin E, Görling A (2018)
Publication Language: English
Publication Status: Published
Publication Type: Journal article
Publication year: 2018
Publisher: AMER PHYSICAL SOC
Book Volume: 98
Pages Range: 205137
Article Number: ARTN 205137
Journal Issue: 20
DOI: 10.1103/PhysRevB.98.205137
Spin-orbit interactions often are taken into account via pseudopotentials or related treatments of core electrons. In this case, the commonly employed Kohn-Sham methods with noncollinear spin are not applicable from a formal point of view. Instead, more general methods in the framework of spin-current density-functional theory (SCDFT) have to be employed. Here, we first review the derivation of SCDFT as a unifying theory that encompasses density-functional theory (DFT) with noncollinear spin, current DFT, and a DFT treatment of currents of the spin. We discuss which parts of SCDFT necessarily have to be taken into account in which physical situation and which parts can be considered on an optional basis. Then, an exact-exchange-only (EXX) SCDFT method (SCEXX) is used to investigate pressure-driven topological phase transition in SnTe and AlBi as representative systems. An estimate of the effect of correlation is obtained by a screening of exchange in the EXX methods. SnTe undergoes a transition from a trivial to a topological insulator, while AlBi is transformed from a topological metal with inverted band edges to a trivial insulator. We show that there is a sizable range of lattice parameters for which electronic structures obtained with noncollinear spin EXX (NCSEXX) and SCEXX belong to different topological classes. Thus, differences between results obtained with NCSEXX and SCEXX, which are due to the consideration of spin currents in SCEXX, are of practical importance in situations when a material simultaneously is characterized by strong spin-orbit interactions and a band ordering governed by small energy differences, e.g., narrow band gaps in semiconductors or small negative gaps in metals with inverted band edges. This is a typical situation for topological materials suggesting to use SCDFT methods for such materials.
APA:
Trushin, E., & Görling, A. (2018). Spin-current density-functional theory for a correct treatment of spin-orbit interactions and its application to topological phase transitions. Physical Review B, 98(20), 205137. https://doi.org/10.1103/PhysRevB.98.205137
MLA:
Trushin, Egor, and Andreas Görling. "Spin-current density-functional theory for a correct treatment of spin-orbit interactions and its application to topological phase transitions." Physical Review B 98.20 (2018): 205137.
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