论文标题
螺旋磁体中介电常数的软木贡贡献
Soft magnon contributions to dielectric constant in spiral magnets with domain walls
论文作者
论文摘要
竞争性磁交换相互作用通常会导致非连接磁性状态，例如自旋螺旋，从而破坏反转对称性并诱导铁电偏振。磁性自由度和介电程度之间产生的强相互作用导致技术在技术上重要的可能性，可以通过电场控制磁性和电磁磁性，而电磁场的电偶极子可以激发磁激发。在这里，我们研究了手性结构壁对螺旋磁体磁电特性的影响。我们使用竞争性的海森堡交换相互作用的准1D模型hamiltonian，导致旋转螺旋和dzyaloshinskii-moriya的相互作用，这对旋转和电动偶极子并混合了磁通和声子激发。结果表明，螺旋磁体中的低频介电异常（例如TBMNO3和MNWO4）可能源自与域壁相关的混合磁子激励。
Competing magnetic exchange interactions often result in non-collinear magnetic states, such as spin spirals, which break the inversion symmetry and induce ferroelectric polarization. The resulting strong interactions between magnetic and dielectric degrees of freedom lead to a technologically important possibility to control magnetic order by electric fields and to electromagnons, magnetic excitations that can be excited by an electric dipole of the electromagnetic field. Here we study the effects of chiral domain walls on magnetoelectric properties of spiral magnets. We use a quasi-1D model Hamiltonian with competing Heisenberg exchange interactions, leading to a spin spiral, and Dzyaloshinskii-Moriya interactions, that couple spins and electric dipoles and mix magnon and phonon excitations. The results suggest that low frequency dielectric anomalies in spiral magnets, such as TbMnO3 and MnWO4, may originate from hybrid magnon - polar phonon excitations associated with domain walls.
