Grainger College of Engineering, All Events

Abstract: Topological physics in hybrid light–matter systems offers a promising route toward future quantum devices. In this talk, I will discuss several examples in which strong light–matter coupling, entanglement, periodic driving, and dissipation give rise to new states and dynamics. First, I will show how strong coupling between cold polar molecules and a microwave cavity produces hybrid photonic-rotational cat states protected by a Z₂ parity symmetry. These entangled light–matter states combine low decoherence with direct relevance for protected bosonic encodings, and can be stabilized under periodic driving even in the presence of loss. As a second example, I will show how Floquet modulation in cavity-coupled tweezer arrays tunes the effective interaction range from long to short, reshaping collective dynamics and opening pathways to strongly correlated states and novel gate protocols. Including cavity dissipation generates correlated decay channels and effective non-Hermitian dynamics, leading to many-body Hatano–Nelson-type models. Finally, I will demonstrate that graphene embedded in a circularly polarized cavity develops topological gaps through coherent light–matter coupling without heating, establishing bulk-boundary correspondence at the single-photon level. Each interaction-induced gap hosts pairs of unidirectional hybrid light–matter edge currents, including bright modes that persist throughout the photon ladder. By time-evolving initially dark electronic edge excitations, I will show how they become bright, coherently propagating chiral currents. I will conclude with a broader perspective on non-equilibrium topology, where non-Abelian braiding across quasienergy gaps gives rise to multigap invariants, such as the Euler class, beyond the usual single-gap picture.

Zoom Link: https://illinois.zoom.us/my/icmt.seminar?pwd=ZU1KbnBLeXZLUmJKc0oyU205cDNDdz09

Meeting ID: 791 382 8328

Password: 106237