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Domain wall of a ferromagnet on a three-dimensional topological insulator.

Wakatsuki R, Ezawa M, Nagaosa N - Sci Rep (2015)

Bottom Line: Most of them come from the peculiar surface or edge states.Especially, the quantized anomalous Hall effect (QAHE) without an external magnetic field is realized in the two-dimensional ferromagnet on a three-dimensional TI which supports the dissipationless edge current.The chirality and relative stability of the Neel wall and Bloch wall depend on the position of the Fermi energy as well as the form of the coupling between the magnetic moments and orbital of the host TI.

View Article: PubMed Central - PubMed

Affiliation: Department of Applied Physics, University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.

ABSTRACT
Topological insulators (TIs) show rich phenomena and functions which can never be realized in ordinary insulators. Most of them come from the peculiar surface or edge states. Especially, the quantized anomalous Hall effect (QAHE) without an external magnetic field is realized in the two-dimensional ferromagnet on a three-dimensional TI which supports the dissipationless edge current. Here we demonstrate theoretically that the domain wall of this ferromagnet, which carries edge current, is charged and can be controlled by the external electric field. The chirality and relative stability of the Neel wall and Bloch wall depend on the position of the Fermi energy as well as the form of the coupling between the magnetic moments and orbital of the host TI. These findings will pave a path to utilize the magnets on TI for the spintronics applications.

No MeSH data available.


Related in: MedlinePlus

Difference of the electron density distribution Δρ(x) (red curve) between the Neel and the Bloch domain wall with equal chemical potential μ.The horizontal axis is the x coordinate. It is well explained by the formula Eq. (25) semi-quantitatively as shown by a black dotted curve. Especially, the dotted curve fits perfectly at tails, where the formula Eq. (25) is expected to be accurate.
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f5: Difference of the electron density distribution Δρ(x) (red curve) between the Neel and the Bloch domain wall with equal chemical potential μ.The horizontal axis is the x coordinate. It is well explained by the formula Eq. (25) semi-quantitatively as shown by a black dotted curve. Especially, the dotted curve fits perfectly at tails, where the formula Eq. (25) is expected to be accurate.

Mentions: To confirm this scenario, we plot the difference in the charge density Δρ(x) between the Neel and Bloch walls with the equal chemical potential in Fig. 5. The formula Eq. (25) captures the key structure of the numerical data as in Fig. 5. Therefore, the peculiar double peak structure in Fig. 4(b) stems from the combination of the chiral edge channel and the spatial variation of the spin texture. The amplitude can be enhanced or reduced, depending on the domain wall type and the filling of the edge channel.


Domain wall of a ferromagnet on a three-dimensional topological insulator.

Wakatsuki R, Ezawa M, Nagaosa N - Sci Rep (2015)

Difference of the electron density distribution Δρ(x) (red curve) between the Neel and the Bloch domain wall with equal chemical potential μ.The horizontal axis is the x coordinate. It is well explained by the formula Eq. (25) semi-quantitatively as shown by a black dotted curve. Especially, the dotted curve fits perfectly at tails, where the formula Eq. (25) is expected to be accurate.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4555097&req=5

f5: Difference of the electron density distribution Δρ(x) (red curve) between the Neel and the Bloch domain wall with equal chemical potential μ.The horizontal axis is the x coordinate. It is well explained by the formula Eq. (25) semi-quantitatively as shown by a black dotted curve. Especially, the dotted curve fits perfectly at tails, where the formula Eq. (25) is expected to be accurate.
Mentions: To confirm this scenario, we plot the difference in the charge density Δρ(x) between the Neel and Bloch walls with the equal chemical potential in Fig. 5. The formula Eq. (25) captures the key structure of the numerical data as in Fig. 5. Therefore, the peculiar double peak structure in Fig. 4(b) stems from the combination of the chiral edge channel and the spatial variation of the spin texture. The amplitude can be enhanced or reduced, depending on the domain wall type and the filling of the edge channel.

Bottom Line: Most of them come from the peculiar surface or edge states.Especially, the quantized anomalous Hall effect (QAHE) without an external magnetic field is realized in the two-dimensional ferromagnet on a three-dimensional TI which supports the dissipationless edge current.The chirality and relative stability of the Neel wall and Bloch wall depend on the position of the Fermi energy as well as the form of the coupling between the magnetic moments and orbital of the host TI.

View Article: PubMed Central - PubMed

Affiliation: Department of Applied Physics, University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.

ABSTRACT
Topological insulators (TIs) show rich phenomena and functions which can never be realized in ordinary insulators. Most of them come from the peculiar surface or edge states. Especially, the quantized anomalous Hall effect (QAHE) without an external magnetic field is realized in the two-dimensional ferromagnet on a three-dimensional TI which supports the dissipationless edge current. Here we demonstrate theoretically that the domain wall of this ferromagnet, which carries edge current, is charged and can be controlled by the external electric field. The chirality and relative stability of the Neel wall and Bloch wall depend on the position of the Fermi energy as well as the form of the coupling between the magnetic moments and orbital of the host TI. These findings will pave a path to utilize the magnets on TI for the spintronics applications.

No MeSH data available.


Related in: MedlinePlus