Casimir-Polder-like Effect in a Superconducting Circuit System

Casimir-type forces arise when the ground state energy of a quantum field depends on a classically-treated degree of freedom. The first example of such forces was proposed by Casimir, when he considered the attractive force that arises between two neutral, conducting plates placed in a vacuum. In this talk, we will discuss a variation of the Casimir-Polder effect, the force between an atom and a conducting plate, in a superconducting circuit consisting of a tunable cavity coupled to a qubit. We will describe an analogous ``Casimir force'' on the cavity's effective boundary condition, outline the consequences of longitudinal versus transverse coupling between the qubit and cavity, and discuss the relevance of the field self-interaction term ($A^{2}$). Finally, we will briefly touch on prospects related to measurement.