Loss-Free Excitonic Quantum Battery

Robust quantum energy storage devices are essential to realize powerful next-generation batteries. Herein, we provide a proof of concept for a loss-free excitonic quantum battery (EQB) by using an open quantum network model that exhibits exchange symmetries linked to its structural topology. By storing electronic excitation energy in a symmetry-protected dark state living in a decoherence-free subspace, one can protect the charged EQB from environment-induced energy losses, thereby making it a promising platform for long-term energy storage. To illustrate the key physical principles and potential functionality of this concept, we consider an open quantum network model of a para-benzene-like structure. We demonstrate through numerical simulations the immunity of the charged EQB to environmentally induced losses and further show how to harness the stored energy by adding a symmetry-breaking perturbation (SBP) to the network. We also investigate the impact of static disorder and temperature fluctuations of the SBP on the performance of the EQB during its storage and discharge phases. Apart from the cases with very strong static disorder, the performance of the EQB is essentially unaltered, thereby demonstrating the robustness of the proposed EQB.