Topologically protected excitons in porphyrin thin films

he control of exciton transport in organic materials is of fundamental importance for the development of efficient light-harvesting systems. This transport is easily deteriorated by traps in the disordered energy landscape. Here, we propose and analyse a system that supports topological Frenkel exci...

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Bibliographic Details
Main Authors: Saikin, Semion K., Yao, Norman Y., Yuen, Joel, Aspuru-Guzik, Alan
Other Authors: Massachusetts Institute of Technology. Research Laboratory of Electronics
Format: Article
Language:en_US
Published: Nature Publishing Group 2015
Online Access:http://hdl.handle.net/1721.1/95950
https://orcid.org/0000-0001-5039-4085
Description
Summary:he control of exciton transport in organic materials is of fundamental importance for the development of efficient light-harvesting systems. This transport is easily deteriorated by traps in the disordered energy landscape. Here, we propose and analyse a system that supports topological Frenkel exciton edge states. Backscattering of these chiral Frenkel excitons is prohibited by symmetry, ensuring that the transport properties of such a system are robust against disorder. To implement our idea, we propose a two-dimensional periodic array of tilted porphyrins interacting with a homogeneous magnetic field. This field serves to break time-reversal symmetry and results in lattice fluxes that mimic the Aharonov–Bohm phase acquired by electrons. Our proposal is the first blueprint for realizing topological phases of matter in molecular aggregates and suggests a paradigm for engineering novel excitonic materials.