论文标题
磁电抗铁磁材料中的矢量电位和表面磁场
Vector Potential and Surface Magnetic Field in Magnetoelectric Antiferromagnetic Materials
论文作者
论文摘要
提出了大量周期系统平均矢量电位的一般公式，并证明可以在磁接口处设置边界条件。对于抗铁磁材料，该研究揭示了由于不同的晶体和磁对称性，宏观电位与方向依赖性磁性四极杆之间的独特关系。特别是，在没有倒置和时间反向对称性的截短的体积的表面和界面上，平均矢量电势表现出不连续性，从而导致界面磁场。然而，由于表面和界面电子和原子弛豫，可能会导致额外的磁化。特别是对于实验观察到的磁电抗铁磁铁，我们的对称分析表明，弛豫效应很可能是对存在这种潜在不连续性的系统响应。
A general formula for the average vector potential of bulk periodic systems is proposed and shown to set the boundary conditions at magnetic interfaces. For antiferromagnetic materials, the study reveals a unique relation between the macroscopic potential and the orientation-dependent magnetic quadrupole, as a result of the different crystalline and magnetic symmetries. In particular, at surfaces and interfaces of a truncated bulk without inversion and time-reversal symmetries, the average vector potential exhibits a discontinuity, which results in an interfacial magnetic field. In general, however, due to the surface and interface electronic and atomic relaxations, additional magnetization may result. For the experimentally-observed magnetoelectric antiferromagnets, in particular, our symmetry analysis suggest that the relaxation effects could well be a system response to the presence of such a potential discontinuity.
