Quantum Optics Seminar: Lewis Ruks

Subwavelength arrays of laser-trapped neutral atoms have emerged as a quantum-optical platform for guiding and shaping light, enabling atoms to assume roles conventionally associated with fabricated waveguides and resonators. These atomic arrays cooperatively respond to incident light through dipole-dipole interactions, effectively functioning as optical elements that additionally exhibit quantum nonlinearities and require descriptions beyond conventional macroscopic media. In this talk, I will introduce the conceptual framework of cooperative quantum-optical atomic arrays interacting with light and present recent theoretical findings demonstrating how unconventional optical phenomena can emerge within a collectively responding atomic medium. 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]. Additionally, we show 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 practical 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. This microscopic approach to atomic lattices as interacting dipoles could enable accurate and computationally efficient design and functionality of nanoscale atomic optical elements and potentially advance novel atom-waveguide hybrid quantum technologies

 

[1] https://www.nature.com/articles/s41467-025-56250-w

[2] https://arxiv.org/abs/2506.13294