论文标题
在电动环偶极子订购下的非线性横向磁敏感性
Nonlinear Transverse Magnetic Susceptibility under Electric Toroidal Dipole Ordering
论文作者
论文摘要
电动环偶极子（ETD）矩是基本偶极矩以及电气和磁性力矩之一。尽管由于其空间反演和时间反转的平等，它既不将电场或磁场直接耦合，但其有序状态导致了共轭物理量的非常规横向反应。在这里，我们在这里研究了ETD排序下的非线性横向磁敏感性。通过在四方晶体电场下对五$ d $轨道模型进行五$ d $ - 轨道模型的自洽均值计算，并使用非线性库比公式进行表明，与外部磁场垂直于外部磁场的均匀磁化值相对应的第三阶横向磁化易感性，一旦ETD稳定在eTD下，则在the eTD下均已下降。此外，我们发现旋转轨道纠缠和低洼的首先激发晶体场水平对于实现较大的横向反应很重要。
An electric toroidal dipole (ETD) moment is one of the fundamental dipole moments as well as electric and magnetic ones. Although it directly couples to neither an electric nor magnetic field due to its spatial inversion and time-reversal parities, its ordered state leads to unconventional transverse responses of the conjugate physical quantities. We here theoretically investigate nonlinear transverse magnetic susceptibility under the ETD ordering. By performing a self-consistent mean-field calculation for a five $d$-orbital model under a tetragonal crystalline electric field and using the nonlinear Kubo formula, we show that a third-order transverse magnetic susceptibility corresponding to a uniform magnetization perpendicular to the external magnetic field becomes nonzero once the ETD moment is ordered under tetragonal crystalline electric field. Moreover, we find that spin-orbital entanglement and a low-lying first excited crystal-field level are important for realizing large transverse responses.
