Coherent Dynamics in Solutions of Colloidal Plexcitonic Nanohybrids at Room Temperature

• Published in: Advanced optical materials Vol. 11; no. 15
• Main Authors: Peruffo, Nicola, Mancin, Fabrizio, Collini, Elisabetta
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01-08-2023
• Subjects: 2D electronic spectroscopy; Coherence; coherent dynamics; colloidal nanoparticles; Colloids; Controllability; Couplings; Electromagnetic fields; Excitons; Fysikalisk kemi; light-matter coupling; Materials science; Nanomaterials; Nonlinear systems; Optical properties; Optics; Photoexcitation; Physical Chemistry; plasmons; plexcitons; polaritons; Quantum phenomena; Room temperature
• ISSN: 2195-1071; 2195-1071
• DOI: 10.1002/adom.202203010

The increasing ability to prepare systems with nanoscale resolution and address their optical properties with ultrashort time precision is revealing quantum phenomena with tremendous potential in quantum nanotechnologies. Colloidal plexcitonic materials promise to play a pivotal role in this scenario. Plexcitons are hybrid states originating from the mixing of the plasmon resonances of metal nanostructures with molecular excitons. They allow nanoscale confinement of electromagnetic fields and the establishment of strong couplings between light and matter, potentially giving rise to controllable and tunable coherent phenomena. However, the characterization of the ultrafast coherent and incoherent dynamics of colloidal plexciton nanohybrids remains highly unexplored. Here, two dimensional electronic spectroscopy (2DES) is employed to study the quantum coherent interactions active after the photoexcitation of these systems. By comparing the response of the nanohybrids with the one of the uncoupled systems, the nonlinear photophysical processes at the base of the coherent dynamics are identified, allowing a step forward toward the effective understanding and exploitation of these nanomaterials.
2D electronic spectroscopy is employed to characterize the ultrafast dynamics of strongly coupled colloidal plexcitonic nanohybrids built by functionalizing gold nanourchins with cyanine dyes in the J‐aggregate form. Clear signatures of coherent interactions between plexcitons are found to dominate the early time dynamics, opening exciting perspectives for the exploitation of these materials for quantum nanophotonic applications.