Light-matter decoupling and $A^2$ term detection in superconducting circuits

Understand

We study the spontaneous emission of a qubit interacting with a one-dimensional waveguide through a realistic minimal-coupling interaction.

• We show that the diamagnetic term $A^2$ leads to an effective decoupling of a single qubit from the electromagnetic field.
• This effects is observable at any range of qubit-photon couplings.
• For this we study a setup consisting of a transmon that is suspended over a transmission line.