Transport processes in molecular systems such as photosynthetic pigments are thought to host quantum coherent environmentally enhanced transport, though experimental proofs are lacking. In this talk I summarize a possible approach to observe the central mechanisms of coherent quantum transfer in such systems via experimental methods achievable in the near term. A crucial function of the environment in enabling enhanced transfer efficiency is inducing directionality in excitation flow, characterised by the violation quantum detailed balance (QDB). We observe in a prototype vibronic dimer model, that the way in which QDB is violated indeed differs between the incoherent and coherent environmental processes enabling transport, with increased contribution from the coherent process aiding faster transport but reducing directional bias. We thus observe a balance between coherent and incoherent processes maximises directional flow over the short timescales involved in exciton transport with biologically relevant conditions. We finally show that the QDB violation, whilst not directly observable in itself for such emitters, may be witnessed through the time-asymmetry of two-colour photon correlations, and that these observable correlations are extremely sensitive to vibrational mode coupling and resonance to exciton energy gaps, present in such systems, yielding a potential route to experimental verification in realistic molecular systems.

The seminar is scheduled to take place on the 26th of November 2024, from 16:15 to 17:15 o’clock, in Room A301, Faculty of Physics, Sofia University ‘St. Kliment Ohridski’.