Mechanism of energy transfer in a hybrid circuit-QED architecture
Phys. Rev. B 114, 225411 – Published 14 October, 2026
DOI: https://doi.org/10.1103/lxjd-4r8x
Abstract
Quantum dot-cavity hybrid systems enable statistics-dependent energy storage in circuit quantum electrodynamics, yet the energy transfer mechanism to an acceptor remains unresolved. Here, we theoretically demonstrate controlled energy release from a voltage-driven donor double quantum dot through a microwave cavity to an acceptor double quantum dot. For fixed cavity-acceptor coupling, when the cavity is prepared in a lasing state, it yields a significant photon population, enhancing the energy transfer to the acceptor. When this population is fixed, a larger cavity-acceptor coupling can further enhance the energy transfer. An increase in joint donor-cavity-acceptor coupling activates virtual-photon-mediated donor-acceptor interactions, which bypass the cavity decay channel and thereby facilitate the energy transfer. Crucially, engineering the acceptor with level spacing larger than the cavity energy enables multiphoton processes that redirect photons to electronic excitations with near-perfect selectivity, suppressing dissipation and boosting energy utilization. Our results provide a blueprint for efficient energy transfer in nanoscale photoelectric devices.
