Quantum scattering theory of Fock states in high-dimensional spaces
  A quantum scattering theory is developed for Fock states scattered by two-level systems in the free space. Compared to existing scattering theories that treat incident light semi-classically, the theory fully quantizes the incident light as Fock states. This non-perturbative method provides exact scattering matrix. 
Jingfeng Liu, Ming Zhou, Zongfu Yu
physics.optics quant-ph