• openAccess   Optimal approximation to unitary quantum operators with linear optics 

      Garcia-Escartin, Juan Carlos; Gimeno, Vicent; Moyano-Fernández, Julio José Springer Nature (2021-09-21)
      Linear optical systems acting on photon number states produce many interesting evolutions, but cannot give all the allowed quantum operations on the input state. Using Toponogov’s theorem from differential geometry, we ...