Realization of Aharonov-Bohm Cages in Photonic Lattices
June 6th, 2019 MARCO DI LIBERTO Université libre de Bruxelles

I will discuss the experimental realization of a uniform synthetic magnetic flux and the observation of Aharonov-Bohm cages in a rhombic array of optical waveguides, where magnetic flux for light is obtained by modulation-assisted tunneling and can be tuned at will by varying the phase of the modulation. In the regime where half a flux quantum is realized in each plaquette, all the energy bands dramatically collapse into nondispersive (flat) bands and all eigenstates are completely localized. We also probe the edge physics where the corresponding edge states can be continuously connected to the topological edge states of the Creutz ladder. Then, I will discuss the impact of local nonlinearities and show that the latter do not break the caging mechanism. As a central result, we focus on special caged solutions, which are accompanied by a breathing motion of the field intensity, that we describe in terms of an effective two-mode model reminiscent of a bosonic Josephson junction. Moreover, we explore the quantum regime using small particle ensembles, and we observe quasi-caged collapse-revival dynamics with negligible leakage. The results stemming from this work open an interesting route towards the characterization of nonlinear dynamics in interacting flat band systems.

Seminar, June 6 2019, 15:00. ICFO’s Seminar Room

Hosted by Prof. Maciej Lewenstein