An electromagnetic field quadrature measurement, performed on one of the modes of the nonlocal single-photon state $\alpha |1,0⟩-\beta |0,1⟩$, collapses it into a superposition of the single-photon and vacuum states in the other mode. We use this effect to implement remote preparation of arbitrary single-mode photonic qubits conditioned on observation of a preselected quadrature value. The preparation efficiency of the resulting qubit can be higher than that of the initial single photon.

• Received 25 August 2003

DOI:https://doi.org/10.1103/PhysRevLett.92.047903