Bath engineering of a fluorescing artificial atom with a photonic crystal

Understand

We demonstrate how the dissipative interaction between a superconducting qubit and a microwave photonic crystal can be used for quantum bath engineering.

• The photonic crystal is created with a step-impedance transmission line which suppresses and enhances the quantum spectral density of states, influencing decay transitions of a transmon circuit.
• The qubit interacts with the transmission line indirectly via dispersive coupling to a cavity.
• We characterize the photonic crystal density of states from both the unitary and dissipative dynamics of the qubit.