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arXiv · 1911.10736

Skyrmion Crystal from RKKY Interaction Mediated by 2D Electron Gas

Zhentao Wang·Ying Su·Shi-Zeng Lin·Cristian D. Batista
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Abstract

We consider a C$_6$ invariant lattice of magnetic moments coupled via a Kondo exchange $J$ with a 2D electron gas (2DEG). The effective Ruderman-Kittel-Kasuya-Yosida interaction between the moments stabilizes a magnetic skyrmion crystal in the presence of magnetic field and easy-axis anisotropy. An attractive aspect of this mechanism is that the magnitude of the magnetic ordering wave vectors, ${\mathbf Q}_ν$ ($ν=1,2,3$), is dictated by the Fermi wave number $k_F$: $|{\mathbf Q}_ν |=2k_F$. Consequently, the topological contribution to the Hall conductivity of the 2DEG becomes of the order of the quantized value, $e^2/h$, when $J$ is comparable to the Fermi energy $ε_F$.

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Zhentao Wang, Ying Su, Shi-Zeng Lin, Cristian D. Batista. 2020-05-19. Skyrmion Crystal from RKKY Interaction Mediated by 2D Electron Gas. https://doi.org/10.1103/physrevlett.124.207201

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