Dual-symmetry breakings including permittivity asymmetry and geometry asymmetry have been studied in all dielectric split-ring metamaterials supported bound states in the continuum. For any single symmetry breaking, the proposed metamaterials can support simultaneously dual quasi-bound states in the continuum (quasi-BICs). Multipolar decomposition reveals that dual quasi-BICs induced by permittivity asymmetry are both governed by magnetic dipole and electric quadrupole, whereas dual quasi-BICs induced by geometry asymmetry are governed by magnetic dipoles. Under the combined effect of the two types of symmetry breaking, it is found that the quasi-BIC can be weaken and vanished, which is different from enhanced quasi-BIC effect induced by a single symmetry breaking. In addition, asymmetric magnetic and electric field distributions can be realized by selecting different type of symmetry breaking, providing a new way of indirectly manipulating the localized magnetic fields. We show that dual-symmetry breakings point to a unique routine to analyze the physical mechanism of quasi-BICs, which furthermore provide a useful insight into their tuning behavior.

中文翻译：

---

在所有介电开口环超材料的连续体中双对称性破坏可调束缚态

在连续体中支持束缚态的所有介电开口环超材料中研究了双对称性破缺，包括介电常数不对称性和几何不对称性。对于任何单个对称性破缺，所提出的超材料可以同时支持连续体中的双准束缚态（准 BIC）。多极分解表明，由介电常数不对称引起的对偶准 BIC 均受磁偶极子和电四极子控制，而由几何不对称引起的对偶准 BIC 受磁偶极子控制。在两种对称性破缺的共同作用下，发现准 BIC 可以减弱甚至消失，这与单一对称性破缺引起的增强准 BIC 效应不同。此外，通过选择不同类型的对称破缺可以实现不对称的磁场和电场分布，提供了一种间接操纵局域磁场的新方法。我们表明，双对称性破缺指向一个独特的例程来分析准 BIC 的物理机制，这进一步提供了对其调整行为的有用见解。