Photon addition
= Photon addition
{title2=$|\psi_+\rangle=a^\dagger|\psi\rangle/\sqrt{\langle N\rangle+1}$}
Ideal conditional application of a <creation operator>, followed by normalization. It reweights the input number distribution as well as raising each occupied number by one. A heralded physical implementation has a success <probability>; the algebraic <creation operator> alone is not a trace-preserving deterministic <quantum operation>.