UKRI-NSF A New Framework for Exploring and Exploiting Quantum Correlations in Molecular Singlet Fission

Quantum mechanics is often thought of in the context of highly controlled laboratory experiments and complicated theoretical calculations. Yet, its principles also govern everyday natural processes. As a consequence, quantum correlations—phenomena like coherence and entanglement that have no classical equivalent—may be the key to dramatically enhancing their efficiency. Hence, this project is devoted to uncovering the hidden potential of quantum mechanics with a particular focus on energy transfer in molecules. Central to our research is the process of singlet fission, where a molecule absorbs a single photon creating an excited state which then divides into two quantum mechanically linked electronic states. This process has the potential to facilitate more efficient charge transfer—a critical step in converting light into electricity. However, despite its significant promise, the intricate mechanisms underlying singlet fission remain largely unexplored, presenting both a challenge and an exciting opportunity for research breakthroughs leading to step changes in technology. Understanding singlet fission poses a dual challenge that intertwines theoretical and experimental obstacles. On the theoretical side, traditional quantum chemistry methods often fall short in capturing the rapid, complex, and non-equilibrium dynamics intrinsic to singlet fission, e.g., where coherence or entanglement play a crucial role. On the experimental side, unraveling the dynamics demands specialized spectroscopic techniques capable of simultaneously resolving both electronic and spin effects over a broad range of timescales. Moreover, the gap between the sophisticated theoretical frameworks of quantum information science and the practical constraints of experimental chemistry is a formidable barrier that this project will overcome: We will integrate cutting-edge modeling with state-of-the-art spectroscopy to achieve a unified understanding of singlet fission. To tackle the challenges outlined above, our project brings together a team with wide-ranging expertise in quantum chemistry, quantum information, open quantum systems, spectroscopy, and synthetic chemistry, to capture the intricate dynamics of singlet fission and the subsequent charge transfer processes. We will develop a novel theoretical framework that combines state-of-the-art quantum chemistry with open quantum systems theory, which will be rigorously tested using cutting-edge ultrafast optical and magnetic resonance spectroscopies on specially-synthesized molecules engineered to exhibit singlet fission. By directly observing the quantum behaviour that drives these processes, we will gain unprecedented insights into optimizing energy transfer and pioneer the integration of quantum information techniques with advanced chemistry research. The potential applications of this research are extensive. A deeper understanding of quantum correlations in singlet fission could lead to the development of next-generation solar cells that significantly exceed current efficiency limits. In addition, these insights may inform the design of photocatalysts and other optoelectronic devices, contributing to more sustainable energy solutions. Beyond immediate technological applications, integrating our new methodology with advanced spectroscopy and chemical synthesis will foster interdisciplinary collaboration, bridging the gap between quantum information theory, chemistry, and materials science, and thereby enriching the broader research community. In summary, our project will combine quantum chemistry with quantum information theory through open quantum systems theory with backing and grounding in experimental measurements to advance fundamental knowledge of quantum dynamics in molecular systems. More, we aspire to translate these insights into practical applications to lay the groundwork for transformative technologies in renewable energy and quantum-enabled devices, ultimately addressing critical challenges in energy conversion and sustainability.