Group seminar at MPQ and Zoom: Tight propagation in layered atomic arrays

Dr. Lewis Ruks, NTT Basic Research Laboratories Theoretical quantum physics research group
Group seminar at MPQ lecture hall and Zoom
Thursday, 21 August, 09:00am (MEZ)

Subwavelength arrays of laser-trapped neutral atoms have emerged as a potential quantum-optical platform for guiding and shaping light, where atoms could assume roles conventionally associated with fabricated optical elements. These atomic arrays cooperatively respond to light through dipole-dipole interactions, exhibit quantum nonlinearities, and can require descriptions beyond conventional macroscopic media. In this talk, I will introduce the conceptual framework of atomic arrays cooperatively interacting with light and present recent theoretical findings demonstrating how unconventional optical phenomena can emerge within a collectively responding and three-dimensional atomic medium formed from layered planar arrays. Specifically, we present negative refraction observed in the deflection of beams[1] and near-zero phase refractive indices that result in substantial increases in the effective optical wavelength[2]. We additionally detail how these effects arise from excitations of collective resonances mediated by dipole-dipole interactions. Unlike conventional materials, where intrinsic imperfections can complicate design and constrain applications associated with these phenomena—such as subwavelength imaging and optical manipulation of quantum emitters—atoms possess precise resonance frequencies and are inherently free from manufacturing imperfections and nonradiative losses. A microscopic approach with atomic lattices as interacting dipoles could enable accurate and computationally efficient design and functionalities to advance nanoscale atomic optical elements.