Entanglement generation between two solid-state qubits mediated by microwave photons

•The qubit-qubit entangled states at the steady-state can be mediated either by real or virtual photons.•The relationship between the reflection coefficient and the concurrence allows to determine a high degree of entanglement.•The generation of qubit-qubit entanglement mediated by a photonic bus is feasible in state-of-the-art experiments. We consider a hybrid system of two interacting double quantum dots coupled to a single-mode microwave resonator, and it is demonstrated that the preparation of qubit–qubit entangled states at the steady-state mediated either by real or virtual photons is feasible when the resonator operates in an over-coupling regime. For that purpose, we perform a comprehensive analysis of the degree of entanglement in the system based on entanglement quantifiers such as the concurrence criterion and the reduced density matrix of the quantum state. In particular, our simulations take into account the current experimental scenario, and special attention is given to the reflection coefficient since it is experimentally accessible. Our findings reveal that when the two qubits energies are close to the resonance, the reflection coefficient becomes unequivocally in a witness of entanglement in the system. Our results pave the way for the experimental that desire to achieve entanglement control in the short- and long-range interactions among qubits.