Dynamical Casimir–Polder force on a partially dressed atom in a cavity comprising a dielectric

• We get the dynamical CP force on a partially dressed atom in a dielectric cavity.
• The force in this cavity is larger than that in infinite dielectric space.
• The force is not symmetric with respect to the center of the cavity.
• The oscillating time of the force increases with the cavity size.

We put a two-level atom into a cavity comprising a dielectric with output coupling. An analytical expression of the dynamical Casimir–Polder force in such a system is obtained when the system starts from a partially dressed state. And the effects of several relevant parameters of the system on the time-dependent force are also discussed.