A synthetic biological quantum optical system

• Published in: Nanoscale Vol. 10; no. 27; pp. 13064 - 13073
• Main Authors: Lishchuk, Anna, Kodali, Goutham, Mancini, Joshua A, Broadbent, Matthew, Darroch, Brice, Mass, Olga A, Nabok, Alexei, Dutton, P Leslie, Hunter, C Neil, Törmä, Päivi, Leggett, Graham J
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 01.01.2018
• Subjects: BASIC BIOLOGICAL SCIENCES; Binding sites; Coupled modes; Coupling; Dimers; Emitters; Excitons; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Light-Harvesting Protein Complexes - chemistry; MATERIALS SCIENCE; Models, Chemical; Optical Devices; Porphyrins; Proteins; Quantum Dots; Quantum Theory; Surface Plasmon Resonance
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c8nr02144a

In strong plasmon-exciton coupling, a surface plasmon mode is coupled to an array of localized emitters to yield new hybrid light-matter states (plexcitons), whose properties may in principle be controlled via modification of the arrangement of emitters. We show that plasmon modes are strongly coupled to synthetic light-harvesting maquette proteins, and that the coupling can be controlled via alteration of the protein structure. For maquettes with a single chlorin binding site, the exciton energy (2.06 ± 0.07 eV) is close to the expected energy of the Qy transition. However, for maquettes containing two chlorin binding sites that are collinear in the field direction, an exciton energy of 2.20 ± 0.01 eV is obtained, intermediate between the energies of the Qx and Qy transitions of the chlorin. This observation is attributed to strong coupling of the LSPR to an H-dimer state not observed under weak coupling.