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The transport and capture of photo-induced electronic excitations is of fundamental interest to the design of energy efficient quantum technologies and to the study of potential quantum effects in biology. Using a simple quantum optical model, we examine the influence of coherence, entanglement, and cooperative dissipation on the transport and capture of excitation energy. We demonstrate that the rate of energy extraction is optimized under conditions that minimize the quantum coherence and entanglement of the system, which is a consequence of spontaneous parity time-reversal symmetry breaking. We then examine the effects of vibrational disorder and show that dephasing can be used to enhance the transport of delocalized excitations in settings relevant to biological photosynthesis. Our results highlight the rich, emergent behavior associated with the quantum-to-classical transition with relevance to the design of room-temperature quantum devices. Published by the American Physical Society2024 

Chirality, or handedness, is a geometrical property denoting a lack of mirror symmetry. Chirality is ubiquitous in nature and is associated with the nonreciprocal interactions observed in complex systems ranging from biomolecules to topological materials. Here, we demonstrate that chiral arrangements of dipole-coupled atoms or molecules can facilitate the helicity-dependent superradiant emission of light. We show that the collective modes of these systems experience an emergent spin-orbit coupling that leads to chirality-dependent photon transport and nontrivial topological properties. These phenomena are fully described within the electric dipole approximation, resulting in very strong optical responses. Our results demonstrate an intimate connection between chirality, superradiance, and photon helicity and provide a comprehensive framework for studying electron transport dynamics in chiral molecules using cold atom quantum simulators. Published by the American Physical Society2024 

Efficient transport and harvesting of excitation energy under low light conditions is an important process in nature and quantum technologies alike. Here we formulate a quantum optics perspective to excitation energy transport in configurations of two-level quantum emitters with a particular emphasis on efficiency and robustness against disorder. We study a periodic geometry of emitter rings with subwavelength spacing, where collective electronic states emerge due to near-field dipole–dipole interactions. The system gives rise to collective subradiant states that are particularly suited to excitation transport and are protected from energy disorder and radiative decoherence. Comparing ring geometries with other configurations shows that the former are more efficient in absorbing, transporting, and trapping incident light. Because our findings are agnostic as to the specific choice of quantum emitters, they indicate general design principles for quantum technologies with superior photon transport properties and may elucidate potential mechanisms resulting in the highly efficient energy transport efficiencies in natural light-harvesting systems.