论文标题
量子磁铁中的二阶磁反应：在交流磁场下磁化
Second-order magnetic responses in quantum magnets: Magnetization under ac magnetic fields
论文作者
论文摘要
我们研究了量子磁铁针对AC磁场的二阶磁反应。我们专注于在不受干扰的汉密尔顿人中保存旋转的$ z $组件，并且在$ xy $ plane中应用了驾驶场。我们发现线性极化的驱动场会引起第二谐波响应，而圆形极化场仅产生零频响应，从而导致磁化强度，并以螺旋度确定的方向。采用公正的数值方法，我们证明了由XXZ模型中圆极化场驱动的非线性磁效应，并表明磁化的大小可以通过线性响应方案中的动力自旋结构因子来预测。
We investigate second-order magnetic responses of quantum magnets against ac magnetic fields. We focus on the case where the $z$ component of the spin is conserved in the unperturbed Hamiltonian and the driving field is applied in the $xy$ plane. We find that linearly polarized driving fields induce a second-harmonic response, while circularly polarized fields generate only a zero-frequency response, leading to a magnetization with a direction determined by the helicity. Employing an unbiased numerical method, we demonstrate the nonlinear magnetic effect driven by the circularly polarized field in the XXZ model and show that the magnitude of the magnetization can be predicted by the dynamical spin structure factor in the linear response regime.
