论文标题
通过应变梯度切换极性金属
Switching a polar metal via strain gradients
论文作者
论文摘要
尽管很少见，但反转对称性的自发分解有时会发生在金属的材料中：这些通常称为极性金属或铁电金属。但是，它们的“极化”不能通过电场切换，这限制了对谱带拓扑的实验控制。在这里，我们将通过第一原理理论调查柔韧性，作为围绕这一障碍的一种可能的方式，它具有众所周知的极性金属lioso $ _3 $。基于原子间力常数的真实空间总和，使用全新的方法计算了该金属的挠曲系数。建造了兰道 - 吉茨堡 - 德文郡型第一原则，并估计要切换该材料的关键弯曲半径，其数量级与Batio $ _3 $相当。
Although rare, spontaneous breakdown of inversion symmetry sometimes occurs in a material which is metallic: these are commonly known as polar metals or ferroelectric metals. Their 'polarization', however, cannot be switched via an electric field, which limits the experimental control over band topology. Here we shall investigate, via first-principles theory, flexoelectricity as a possible way around this obstacle with the well known polar metal LiOsO$_3$. The flexocoupling coefficients are computed for this metal with high accuracy with a completely new approach based on real-space sums of the inter-atomic force constants. A Landau-Ginzburg-Devonshire-type first-principles Hamiltonian is built and a critical bending radius to switch the material is estimated, whose order of magnitude is comparable to that of BaTiO$_3$.
