Abstract Circular dichroism (CD) is widely used in bio-sensing, pharmaceuticals, and molecular chemistry. Symmetry breaking is an important method of achieving CD signals. However, the relationship between the magnitude of CD and symmetry breaking remains unclear. In this study, we introduce nanorods into symmetric nanostructures comprising vertical Q-shaped nanostructure arrays (VQNAs) to prove the relativity of the symmetry breaking. The numerical simulations results show that the CD spectra of VQNAs present four modes in the visible spectrum. The coupling between nanorods differs under left- and right-handed circular polarized illuminations, leading to the production of the CD. The CD magnitude is not monotonic when the parameters of VQNAs change, and it is the largest for the structure at an appropriate scale. Besides, VQNAs have stable optical properties. Results can help to understand more deeply the CD mechanism produced by symmetry breaking, and design chiral plasmonic nanostructures.

中文翻译：

---

垂直Q形纳米结构中可调对称性破坏引起的圆二色性

摘要 圆二色性（CD）广泛应用于生物传感、药物和分子化学。对称破坏是实现CD信号的重要方法。然而，CD 的大小与对称性破缺之间的关系仍不清楚。在这项研究中，我们将纳米棒引入包含垂直 Q 形纳米结构阵列 (VQNA) 的对称纳米结构中，以证明对称性破坏的相对性。数值模拟结果表明，VQNA 的 CD 光谱在可见光谱中呈现出四种模式。纳米棒之间的耦合在左旋和右旋圆偏振照明下不同，导致 CD 的产生。当 VQNA 的参数变化时，CD 幅度不是单调的，在适当的尺度下，它是结构最大的。除了，VQNA 具有稳定的光学特性。结果有助于更深入地理解对称破坏产生的CD机制，并设计手性等离子体纳米结构。