Cavity driven by a single photon: conditional dynamics and non-linear   phase shift
  We apply the stochastic master equations (quantum filter) derived by Gough et al. (Proc. 50th IEEE Conference on Decision and Control, 2011) to a system consisting of a cavity driven by a multimode single photon field. In particular, we analyse the conditional dynamics for the problem of cross phase modulation in a doubly resonant cavity. Through the exact integration of the stochastic equations, our results reveal features of the problem unavailable from previous models. 
A. R. R. Carvalho, M. R. Hush and M. R. James
quant-ph