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Control of Dzyaloshinskii-Moriya interaction in Mn(1-x)Fe(x)Ge: a first-principles study.

Koretsune T, Nagaosa N, Arita R - Sci Rep (2015)

Bottom Line: Motivated by the recent experiment on the size and helicity control of skyrmions in Mn(1-x)Fe(x)Ge, we study how the Dzyaloshinskii-Moriya (DM) interaction changes its size and sign in metallic helimagnets.By means of first-principles calculations, we successfully reproduce the non-trivial sign change of the DM interaction observed in the experiment.While the DM interaction sensitively depends on the carrier density or the detail of the electronic structure such as the size of the exchange splitting, its behavior can be systematically understood in terms of the distribution of anticrossing points in the band structure.

View Article: PubMed Central - PubMed

Affiliation: RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan.

ABSTRACT
Motivated by the recent experiment on the size and helicity control of skyrmions in Mn(1-x)Fe(x)Ge, we study how the Dzyaloshinskii-Moriya (DM) interaction changes its size and sign in metallic helimagnets. By means of first-principles calculations, we successfully reproduce the non-trivial sign change of the DM interaction observed in the experiment. While the DM interaction sensitively depends on the carrier density or the detail of the electronic structure such as the size of the exchange splitting, its behavior can be systematically understood in terms of the distribution of anticrossing points in the band structure. By following this guiding principle, we can even induce gigantic anisotropy in the DM interaction by applying a strain to the system. These results pave the new way for skyrmion crystal engineering in metallic helimagnets.

No MeSH data available.


Related in: MedlinePlus

Carrier density dependence of the DM interaction starting from MnGe electronic structure.Carrier density dependence of the DM interaction coefficients, , and . We use the electronic structure of MnGe (n = 0.0) for the same crystal structure as that of FeGe and employ the rigid band approximation. n = 1.0 (μ = 0.832 eV) corresponds to the carrier density of FeGe.
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f7: Carrier density dependence of the DM interaction starting from MnGe electronic structure.Carrier density dependence of the DM interaction coefficients, , and . We use the electronic structure of MnGe (n = 0.0) for the same crystal structure as that of FeGe and employ the rigid band approximation. n = 1.0 (μ = 0.832 eV) corresponds to the carrier density of FeGe.

Mentions: In the present calculation, we employed the rigid band approximation. To examine its validity, we have performed a calculation for the other end material MnGe and doped negative carriers by the rigid band approximation. As shown in Fig. 7, we have obtained a qualitatively similar result in that is positive (negative) for the end material MnGe (FeGe). Thus the result that for Mn1−xFexGe changes its sign between x = 0 and 1 should be robust, even when we go beyond the rigid band approximation.


Control of Dzyaloshinskii-Moriya interaction in Mn(1-x)Fe(x)Ge: a first-principles study.

Koretsune T, Nagaosa N, Arita R - Sci Rep (2015)

Carrier density dependence of the DM interaction starting from MnGe electronic structure.Carrier density dependence of the DM interaction coefficients, , and . We use the electronic structure of MnGe (n = 0.0) for the same crystal structure as that of FeGe and employ the rigid band approximation. n = 1.0 (μ = 0.832 eV) corresponds to the carrier density of FeGe.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4548439&req=5

f7: Carrier density dependence of the DM interaction starting from MnGe electronic structure.Carrier density dependence of the DM interaction coefficients, , and . We use the electronic structure of MnGe (n = 0.0) for the same crystal structure as that of FeGe and employ the rigid band approximation. n = 1.0 (μ = 0.832 eV) corresponds to the carrier density of FeGe.
Mentions: In the present calculation, we employed the rigid band approximation. To examine its validity, we have performed a calculation for the other end material MnGe and doped negative carriers by the rigid band approximation. As shown in Fig. 7, we have obtained a qualitatively similar result in that is positive (negative) for the end material MnGe (FeGe). Thus the result that for Mn1−xFexGe changes its sign between x = 0 and 1 should be robust, even when we go beyond the rigid band approximation.

Bottom Line: Motivated by the recent experiment on the size and helicity control of skyrmions in Mn(1-x)Fe(x)Ge, we study how the Dzyaloshinskii-Moriya (DM) interaction changes its size and sign in metallic helimagnets.By means of first-principles calculations, we successfully reproduce the non-trivial sign change of the DM interaction observed in the experiment.While the DM interaction sensitively depends on the carrier density or the detail of the electronic structure such as the size of the exchange splitting, its behavior can be systematically understood in terms of the distribution of anticrossing points in the band structure.

View Article: PubMed Central - PubMed

Affiliation: RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan.

ABSTRACT
Motivated by the recent experiment on the size and helicity control of skyrmions in Mn(1-x)Fe(x)Ge, we study how the Dzyaloshinskii-Moriya (DM) interaction changes its size and sign in metallic helimagnets. By means of first-principles calculations, we successfully reproduce the non-trivial sign change of the DM interaction observed in the experiment. While the DM interaction sensitively depends on the carrier density or the detail of the electronic structure such as the size of the exchange splitting, its behavior can be systematically understood in terms of the distribution of anticrossing points in the band structure. By following this guiding principle, we can even induce gigantic anisotropy in the DM interaction by applying a strain to the system. These results pave the new way for skyrmion crystal engineering in metallic helimagnets.

No MeSH data available.


Related in: MedlinePlus