• openAccess   Multiple photon effective Hamiltonians in linear quantum optical networks 

      García-Escartín, Juan Carlos; Gimeno, Vicent; Moyano-Fernández, Julio José Elsevier (2019)
      We give an alternative derivation for the explicit formula of the effective Hamiltonian describing the evolution of the quantum state of any number of photons entering a linear optics multiport. The description is based ...
    • openAccess   No-go theorems for photon state transformations in quantum linear optics 

      V. Parellada, Pablo; Gimeno i Garcia, Vicent; Moyano-Fernández, Julio José; Garcia-Escartin, Juan Carlos Elsevier (2023)
      We give a necessary condition for photon state transformations in linear optical setups preserving the total number of photons. From an analysis of the algebra describing the quantum evolution, we find a conserved quantity ...