A toroidal dipole represents an often overlooked electromagnetic excitation distinct from the standard electric and magnetic multipole expansion. We show how a simple arrangement of strongly radiatively coupled atoms can be used to synthesize a toroidal dipole where the toroidal topology is generated by radiative transitions forming an effective poloidal electric current wound around a torus. We extend the protocol for methods to prepare a delocalized collective excitation mode consisting of a synthetic lattice of such toroidal dipoles and a nonradiating, yet oscillating charge-current configuration, dynamic anapole, for which the far-field radiation of a toroidal dipole is identically canceled by an electric dipole.

中文翻译：

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原子集体响应阵列中的辐射环形偶极和偶极激发。

环形偶极子代表了一种经常被忽视的电磁激励，它不同于标准的电和磁多极膨胀。我们展示了如何使用强辐射耦合原子的简单排列方式来合成环形偶极子，其中环形拓扑是通过辐射跃迁生成的，该辐射跃迁形成缠绕在圆环上的有效多倍体电流。我们扩展了协议的方法，以准备由此类环形偶极子的合成晶格和无辐射但振荡的电荷电流配置动态偶极子组成的离域集体激发模式，为此，环形偶极子的远场辐射被相同地抵消了通过电偶极子。