title: Noise-free measurement of harmonic oscillators with instantaneous interactions.
abstract: We present a method of measuring the quantum state of a harmonic oscillator through instantaneous probe-system selective interactions of the Jaynes-Cummings type. We prove that this scheme is robust to general decoherence mechanisms, allowing the possibility of measuring fast-decaying systems in the weak-coupling regime. This method could be applied to different setups: motional states of trapped ions, microwave fields in cavity or circuit QED, and even intracavity optical fields.
authors.affiliation: Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil. msantos@fisica.ufmg.br
authors.forename: M
authors.initials: M
authors.lastname: França Santos
authors.forename: G
authors.initials: G
authors.lastname: Giedke
authors.forename: E
authors.initials: E
authors.lastname: Solano