Materials Theory, ETH Zurich, Wolfgang-Pauli-Strasse 27, CH-8093 Zurich, Switzerland.
Phys Rev Lett. 2012 Nov 9;109(19):197203. doi: 10.1103/PhysRevLett.109.197203. Epub 2012 Nov 8.
We use symmetry analysis and first-principles calculations to show that the linear magnetoelectric effect can originate from the response of orbital magnetic moments to the polar distortions induced by an applied electric field. Using LiFePO(4) as a model compound we show that spin-orbit coupling partially lifts the quenching of the 3d orbitals and causes small orbital magnetic moments (μ((L)) ≈ 0.3 μ(B)) parallel to the spins of the Fe(2+) ions. An applied electric field E modifies the size of these orbital magnetic moments inducing a net magnetization linear in E.
我们利用对称分析和第一性原理计算表明，线性磁电效应可能源于轨道磁矩对由外加电场引起的极化畸变的响应。我们选用 LiFePO4 作为模型化合物，表明自旋轨道耦合部分消除了 3d 轨道的猝灭，并导致与 Fe(2+)离子自旋平行的小轨道磁矩（μ((L)) ≈ 0.3 μ(B)）。外加电场 E 会改变这些轨道磁矩的大小，从而诱导出与 E 线性相关的净磁化强度。
