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arXiv · 1202.2127

Itinerant half-metal spin-density-wave state on the hexagonal lattice

Rahul Nandkishore·Gia-Wei Chern·Andrey V. Chubukov
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Abstract

We consider electrons on a honeycomb or triangular lattice doped to the saddle point of the bandstructure. We assume system parameters are such that spin density wave (SDW) order emerges below a temperature $T_N$ and investigate the nature of the SDW phase. We argue that at $T < T_N$ the system develops a uniaxial SDW phase whose ordering pattern breaks $O(3) \times Z_4$ symmetry and corresponds to an eight site unit cell with non-uniform spin moments on different sites. This state is a half-metal -- it preserves full original Fermi surface, but has gapless charged excitations in one spin branch only. It allows for electrical control of spin currents and is desirable for nano-science.

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Rahul Nandkishore, Gia-Wei Chern, Andrey V. Chubukov. 2012-02-09. Itinerant half-metal spin-density-wave state on the hexagonal lattice. https://doi.org/10.1103/physrevlett.108.227204

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