A method and apparatus for quantum information processing is disclosed in which logical qubits |0>.sub.L and |1>.sub.L are respectively encoded by different near orthogonal coherent states |.beta.> and |.alpha.>, where <.alpha.|.beta.>=0, |.alpha.> and |.beta.> being the computational basis states for the qubits, for example, in which logical qubits |0>.sub.L and |1>.sub.L are respectively encoded by different ones of the vacuum state |0> and a multi-photon optical coherent state |.alpha.> which states are the computational basis states for the qubits. This provide an efficient scheme for linear optics quantum processing which is deterministic and for which qubit readout can use homodyne detection which is highly efficient. The invention finds application in quantum computation and quantum communication.