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Scientific Reports 9, 14301 (2019)

ISSN: 2045-2322, SCI

Efcient production of large-size optical Schrödinger cat states

Evgeny V. Mikheev, Alexander S. Pugin, Dmitry A. Kuts, Sergey A. Podoshvedov & Nguyen Ba An

We present novel theory of efective realization of large-size optical Schrödinger cat states, which play an important role for quantum communication and quantum computation in the optical domain using laser sources. The treatment is based on the α-representation in infnite Hilbert space which is the decomposition of an arbitrary quantum state in terms of displaced number states characterized by the displacement amplitude α. We fnd analytical form of the α-representation for both even and odd Schrödinger cat states which is essential for their generation schemes. Two schemes are proposed for generating even/odd Schrödinger cat states of large size |β| (|β|≥2) with high fdelity F (F≈0.99). One scheme relies on an initially ofine prepared two-mode entangled state with a fxed total photon number, while the other scheme uses separable photon Fock states as the input. In both schemes, generation of the desired states is heralded by the corresponding measurement outcomes. Conditions for obtaining states useful for quantum information processing are established and success probabilities for their generation are evaluated.

DOI: 10.1038/s41598-019-50703-1