The chirality of an object can be studied by measuring the circular dichroism, that is, the difference in absorption of light with different helicity. The chiral optical response of an object, however, can have two different origins. On the one hand, it can be linked to the chiral geometry of the object. On the other hand, it can be linked to the chiral material from which the object is made. Whereas previously no distinction between the two contributions could be made, we report here a computational approach that allows us to separate these two contributions to the circular dichroism of an object. We consider separately the case where geometry-related resonances affect the optical response and the case where they are absent. In both cases, we find the circular dichroism to be easily decomposable if a geometrically achiral object has an absorption spectrum similar to that of the chiral object under investigation. Furthermore, in the nonresonant case, the contribution attributed to the material can be obtained without taking any geometry into account. Besides being of fundamental importance, the possibility of disentangling both contributions will be important for guiding the future design of chiral objects and devices.

中文翻译：

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分离材料和几何对手性介质制成的手性物体圆二色性的贡献

物体的手性可以通过测量圆二色性来研究，即不同螺旋度的光吸收差异。然而，物体的手性光学响应可以有两个不同的来源。一方面，它可以与物体的手性几何形状联系起来。另一方面，它可以与制造该物体的手性材料联系起来。虽然以前无法区分这两种贡献，但我们在此报告了一种计算方法，该方法允许我们将这两种对物体圆二色性的贡献分开。我们分别考虑几何相关共振影响光学响应的​​情况和不存在几何相关共振的情况。在这两种情况下，我们发现如果几何非手性物体具有与所研究的手性物体相似的吸收光谱，则圆二色性很容易分解。此外，在非谐振情况下，无需考虑任何几何形状即可获得材料的贡献。除了具有根本重要性之外，区分这两种贡献的可能性对于指导手性物体和设备的未来设计也很重要。