Quantum phase estimation using a multi-headed cat state

Su Yong Lee, Chang Woo Lee, Hyunchul Nha, Dagomir Kaszlikowski

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14 Citations (Scopus)


It was recently shown that an entangled coherent state, which is a superposition of two different coherent states, can surpass the performance of noon state in estimating an unknown phase shift. This may hint at further enhancement in phase estimation by incorporating more component states in the superposition of resource state. We here introduce a four-headed cat state (4HCS), a superposition of four different coherent states, and propose its application to quantum phase estimation. We demonstrate the enhanced performance in phase estimation by employing an entangled state via the 4HCS, which can surpass that of the two-headed cat state (2HCS), particularly in the regime of small average photon numbers. Moreover, we show that an entangled state modified from the 4HCS can further enhance the phase estimation, even in the regime of large average photon number under a photon-loss channel. Our investigation further extends to incorporate an increasingly large number of component states in the resource superposition state and clearly show its merit in phase estimation.

Original languageEnglish
Pages (from-to)1186-1192
Number of pages7
JournalJournal of the Optical Society of America B: Optical Physics
Issue number6
Publication statusPublished - 1 Jun 2015


ASJC Scopus subject areas

  • Statistical and Nonlinear Physics
  • Atomic and Molecular Physics, and Optics

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