Dynamical Casimir effect with δ − δ ′ mirrors

We calculate the spectrum and the total rate of created particles for a real massless scalar field in 1+1 dimensions, in the presence of a partially transparent moving mirror simulated by a Dirac δ−δ′ point interaction. We show that, for this model, a partially reflecting mirror can produce a larger number of particles in comparison with a perfect one. In the limit of a perfect mirror, our formulas recover those found in the literature for the particle creation by a moving mirror with a Robin boundary condition.