Skip to Main content Skip to Navigation
Journal articles

Generation of optical 'Schrödinger cats' from photon number states

Abstract : Schrödinger's cat is a Gedankenexperiment in quantum physics, in which an atomic decay triggers the death of the cat. Because quantum physics allow atoms to remain in superpositions of states, the classical cat would then be simultaneously dead and alive. By analogy, a 'cat' state of freely propagating light can be defined as a quantum superposition of well separated quasiclassical states--it is a classical light wave that simultaneously possesses two opposite phases. Such states play an important role in fundamental tests of quantum theory and in many quantum information processing tasks, including quantum computation, quantum teleportation and precision measurements. Recently, optical Schrödinger'kittens' were prepared; however, they are too small for most of the aforementioned applications and increasing their size is experimentally challenging. Here we demonstrate, theoretically and experimentally, a protocol that allows the generation of arbitrarily large squeezed Schrödinger cat states, using homodyne detection and photon number states as resources. We implemented this protocol with light pulses containing two photons, producing a squeezed Schrödinger cat state with a negative Wigner function. This state clearly exhibits several quantum phase-space interference fringes between the 'dead' and 'alive' components, and is large enough to become useful for quantum information processing and experimental tests of quantum theory
Document type :
Journal articles
Complete list of metadatas
Contributor : Marie-Laure Edwards <>
Submitted on : Thursday, April 19, 2012 - 5:52:31 PM
Last modification on : Wednesday, September 16, 2020 - 5:43:30 PM

Links full text




Alexei Ourjoumtsev, Hyunseok Jeong, Rosa Tualle-Brouri, Philippe Grangier. Generation of optical 'Schrödinger cats' from photon number states. Nature, Nature Publishing Group, 2007, 448, pp.784-786. ⟨10.1038/nature06054⟩. ⟨hal-00689675⟩



Record views