Canonical magnetic insulators with isotropic magnetoelectric coupling

Article

关键词: NEUTRON-DIFFRACTION;    OXYGEN VACANCIES;    PYROCHLORES;    NI;   

DOI  :  10.1103/PhysRevB.88.121106

来源: SCIE

【 摘 要 】

We have performed a systematic representation-theory-based search for the simplest structures allowing isotropic magnetoelectric coupling. We find 30 such structures, all sharing a common pattern of atomic displacements in the direction of atomic magnetic moments. We focus on one of these 30 canonical structures and find that it is generically realized in a class of fractionally substituted pyrochlore compounds with an all-in-all-out magnetic order. Furthermore, we find that these substituted pyrochlore compounds have a substantial Chern-Simons orbital magnetoelectric component (theta = 0.1-0.2). While this component is also formally present in strong Z(2) topological insulators (theta = pi), its effects are observable there only if time-reversal symmetry is broken at the surface.

【 授权许可】

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