title: Generation and tomography of arbitrary optical qubits using transient collective atomic excitations.
abstract: We demonstrate the preparation of heralded Fock-basis qubits (a|0〉+b|1〉) from transient collective spin excitations in a hot atomic vapor. The preparation event is heralded by Raman-scattered photons in a four-wave mixing process seeded by a weak coherent optical excitation. The amplitude and phase of the seed field allow arbitrary control over the qubit coefficients. The qubit state is characterized using balanced homodyne tomography.
authors.forename: T
authors.initials: T
authors.lastname: Brannan
authors.forename: Z
authors.initials: Z
authors.lastname: Qin
authors.forename: A
authors.initials: A
authors.lastname: MacRae
authors.forename: A I
authors.initials: AI
authors.lastname: Lvovsky