Dynamical Casimir effect with $\delta-\delta^{\prime}$ 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 $\delta-\delta^{\prime}$ 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. 
Jeferson Danilo L. Silva, Alessandra N. Braga, Danilo T. Alves
quant-ph hep-th math-ph math.MP