title: Harmonic entanglement with second-order nonlinearity.
abstract: We investigate the second-order nonlinear interaction as a means to generate entanglement between fields of differing wavelengths and show that perfect entanglement can, in principle, be produced between the fundamental and second-harmonic fields in these processes. Neither pure second-harmonic generation nor parametric oscillation optimally produce entanglement; such optimal entanglement is rather produced by an intermediate process.
authors.affiliation: Quantum Optics Group, Department of Physics, Faculty of Science, The Australian National University, ACT 0200, Australia.
authors.forename: Nicolai B
authors.initials: NB
authors.lastname: Grosse
authors.forename: Warwick P
authors.initials: WP
authors.lastname: Bowen
authors.forename: Kirk
authors.initials: K
authors.lastname: McKenzie
authors.forename: Ping Koy
authors.initials: PK
authors.lastname: Lam