Distinguishing two single-mode Gaussian states by homodyne detection: An information-theoretic approach

Hyunchul Nha, H. J. Carmichael

Research output: Contribution to journalArticle

24 Citations (Scopus)


It is known that quantum fidelity, as a measure of the closeness of two quantum states, is operationally equivalent to the minimal overlap of the probability distributions of the two states over all possible positive-operator-valued measures (POVM's); the POVM realizing the minimum is optimal. We consider the ability of homodyne detection to distinguish two single-mode Gaussian states and investigate to what extent it is optimal in this information-theoretic sense. We completely identify the conditions under which homodyne detection makes an optimal distinction between two single-mode Gaussian states of the same mean and show that, if the Gaussian states are pure, they are always optimally distinguished.

Original languageEnglish
Article number032336
JournalPhysical Review A - Atomic, Molecular, and Optical Physics
Issue number3
Publication statusPublished - 1 Mar 2005
Externally publishedYes


ASJC Scopus subject areas

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

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