Distinguishing Schrödinger cats in a lossy environment

A. Gábris, P. Adam, M. Koniorczyk, J. Janszky

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6 Citations (Scopus)


Optical Schrödinger cat states - that is, even and odd coherent states - are considered as possible candidates for forming a computational basis for a coherent state qubit. The distinguishability of the two originally orthogonal states after experiencing loss is quantified in terms of quantum relative entropy. This is a physically instructive quantity related to probabilities of faults in identifying the state. This distinguishability is important for classical communication and for the problem of reading out the result of a quantum computation by a lossy device. It is shown that the distinguishability can significantly increase if the environment is prepared in an appropriately chosen squeezed state.

Original languageEnglish
Pages (from-to)S84-S89
JournalJournal of Optics B: Quantum and Semiclassical Optics
Issue number3
Publication statusPublished - Mar 1 2004



  • Coherent state superposition
  • Decoherence
  • Optical qubit
  • Quantum information
  • Quantum relative entropy
  • Squeezed state

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Physics and Astronomy (miscellaneous)

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