Polariton states in circuit QED for electromagnetically induced transparency

Understand

Electromagnetically induced transparency (EIT) has been extensively studied in various systems.

• However, it is not easy to observe in superconducting quantum circuits (SQCs), because the Rabi frequency of the strong controlling field corresponding to EIT is limited by the decay rates of the SQCs.
• Here, we show that EIT can be achieved by engineering decay rates in a superconducting circuit QED system through a classical driving field on the qubit.
• Without such a driving field, the superconducting qubit and the cavity field are approximately decoupled in the large detuning regime, and thus the eigenstates of the system are approximately product states of the cavity field and qubit states.