Olaya-Castro leads theoretical research on quantum phenomena in biological systems. Research directions: (1) Quantum coherence in photosynthesis — open quantum systems theory for energy transfer in light-harvesting complexes, probing whether quantum coherence provides functional advantage; vibronic coupling models for chromophore-protein complexes; (2) Counting statistics and noise in exciton and charge transfer; (3) Quantum thermodynamics of biomolecular machines — efficiency limits and entropy production in molecular motors; (4) Non-classical features of electronic/vibrational dynamics in chromophores; (5) Connections between quantum information measures and biological function. Collaborates with Bain and Llorente-Garcia on joint experiment/theory biosensing projects. Theoretical work only — no experimental activity.