Quantum batteries are nanoscale systems that store and release energy by exploiting uniquely quantum mechanical features such as coherence, entanglement, and symmetry. In this presentation, I will give an overview of our group’s work on excitonic quantum batteries, built from coupled quantum systems that store excitation energy in symmetry-protected dark states which do not emit light and are therefore long-lived. I will introduce the basic concepts using chemically intuitive ring and stacked-ring motifs, and show how a simple laser-charging protocol can funnel energy into dark states via nearby bright states. Using open quantum dynamics simulations, we demonstrate that these dark states can store energy, not just excited-state population, with minimal loss, and that energy can be released on demand by introducing controlled symmetry-breaking perturbations.

I will then discuss how battery geometry, coupling strengths, laser timing, and disorder (static defects, thermal motion, dephasing) affect charging, storage, and discharge, and identify design rules and operating windows that should be accessible in real systems such as molecular aggregates, excitonic materials, or designer nanostructures. Finally, I will highlight our recent work on tailoring the coupling between the battery and an energy sink to enhance exciton extraction rates, and on constructing chemically explicit exciton models parametrized from electronic structure calculations. Together, these studies provide practical design principles for experimentally testable excitonic quantum battery architectures.

References
[1] Khodadad, Z; Hanna, G. (2026). "Enhancing exciton transfer efficiency in an open quantum battery via architecture engineering". J. Chem. Phys. 164: 064305.
[2] Mena, H.; Khodadad, Z.; Zeng, T.; Hanna, G. (2025). "Molecular Models of Symmetry-Protected Quantum Batteries: Electronic Structure and Exciton Dynamics". J. Chem. Theory Comput. 21: 12443-12452.
[3] Khodadad, Z; Samimi, S; Hanna, G. (2025). "Impact of network architecture on the exciton dynamics in an open quantum battery". J. Chem. Phys. 163: 084305.
[4] Khodadad, Z; Mahdian, M; Hanna, G. (2025). "Dark excitonic state preparation in a symmetry-protected open quantum battery". Adv. Quantum Technol. 8: e00211.
[5] Khodadad, Z; Tarabishi, J; Hanna, G. (2025). "Impact of disorder on the exciton dynamics of an open quantum battery". J. Chem. Phys. 162: 074309-1 - 074309-10.
[6] Liu, Z; Hanna, G. (2024). "Population and Energy Transfer Dynamics in an Open Excitonic Quantum Battery". Molecules. 29: 889.
[7] Liu, J.; Segal, D.; Hanna, G. (2019) "Loss-free excitonic quantum battery" J. Phys. Chem. C. 123: 18303-18314.