The emergence of collective order in matter is among the most fundamental and intriguing phenomena in physics. In recent years, the dynamical control and creation of novel ordered states of matter not accessible in thermodynamic equilibrium is receiving much attention^1,2,3,4,5,6. The theoretical concept of dynamical multiferroicity has been introduced to describe the emergence of magnetization due to time-dependent electric polarization in non-ferromagnetic materials^7,8. In simple terms, the coherent rotating motion of the ions in a crystal induces a magnetic moment along the axis of rotation. Here we provide experimental evidence of room-temperature magnetization in the archetypal paraelectric perovskite SrTiO₃ due to this mechanism. We resonantly drive the infrared-active soft phonon mode with an intense circularly polarized terahertz electric field and detect the time-resolved magneto-optical Kerr effect. A simple model, which includes two coupled nonlinear oscillators whose forces and couplings are derived with ab initio calculations using self-consistent phonon theory at a finite temperature⁹, reproduces qualitatively our experimental observations. A quantitatively correct magnitude was obtained for the effect by also considering the phonon analogue of the reciprocal of the Einstein–de Haas effect, which is also called the Barnett effect, in which the total angular momentum from the phonon order is transferred to the electronic one. Our findings show a new path for the control of magnetism, for example, for ultrafast magnetic switches, by coherently controlling the lattice vibrations with light.

物质集体秩序的出现是物理学中最基本、最有趣的现象之一。近年来，热力学平衡中无法实现的新型有序物质态的动态控制和创建受到了广泛关注^1,2,3,4,5,6。动态多铁性的理论概念被引入来描述由于非铁磁材料中随时间变化的电极化而产生的磁化强度^7,8。简而言之，晶体中离子的相干旋转运动会沿旋转轴感应出磁矩。在这里，我们提供了由于这种机制而在原型顺电钙钛矿 SrTiO ₃中实现室温磁化的实验证据。我们用强圆偏振太赫兹电场共振驱动红外活性软声子模式，并检测时间分辨磁光克尔效应。一个简单的模型包括两个耦合的非线性振荡器，其力和耦合是在有限温度下使用自洽声子理论⁹从头计算得出的，定性地再现了我们的实验观察结果。通过考虑爱因斯坦-德哈斯效应倒数的声子模拟（也称为巴尼特效应），获得了该效应的定量正确幅度，其中声子级的总角动量转移到电子级。我们的研究结果揭示了一种控制磁性的新途径，例如通过用光连贯地控制晶格振动来实现超快磁性开关。