Novel dynamics of optical manipulation in nano-architected objects

Light can be a powerful tool to mechanically manipulate matter, as evidenced by concepts such as optical tweezers and optical traps utilized across biology, colloidal science, microfuidics, and elsewhere. Advances in nanofabrication have enabled the ability to engineer the phase front of light as well as structure the shape of the target object for more advanced mechanical manipulation. We show how the combination of phase-space topology and particle asymmetry can provide a powerful degree of freedom in designing nanoparticles for optimal external manipulation. In particular, we find counterintuitive dynamics where optically asymmetric particles become stable nanoscale motors even in a light field with zero angular momentum. Here, the wavelength of the incident light can be used to externally control the number, orientation, and the stability of the equilibrium states. Finally, we discuss how structural complexity on the nano-scale can enable rich dynamics of optical manipulation of objects much larger than a wavelength in size.