(115d) Chiral Nanocrystals and Metamaterials

Optical nanomaterials offer the ability to bend, twist, guide, and confine light in nanoscale dimensions, leading to new applications in photovoltaics, sensing, light emission, and other optoelectronic devices.

This talk will discuss the development of chiral nanomaterials that interact selectively with right and left handed circularly polarized light. Chiral molecules typically have small dissymmetry factors, due to the mismatch in size between the helical pitch of circularly polarized light and the size of the molecule. Chiral nanomaterials, in contrast, exhibit orders of magnitude stronger dissymmetry factors but have only been realized in a limited set of materials systems. I will show two different examples of nanoscale chiral systems that are tunable and potentially switchable. In the first, binding a series of different chiral carboxylic acid ligands to the surface of a semiconductor nanocrystal results in a 30x change in dissymmetry factors. In the second example, I will show chiral metamaterials that incorporate both metal and dielectric components, where the sign and magnitude of the circular dichroism response depends on the refractive index of the dielectric component. Finally, I will discuss measurements of circularly polarized luminescence from achiral quantum dots coupled to chiral metamaterials.