2015/01/22 by Sergey A. Podoshvedov, Podoshvedov, Sergey A.
Computer Science · Engineering · Physics and Astronomy · #FOS: Physical sciences #Photonic and Optical Devices #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum Physics (quant-ph) #quant-ph
paper · pdf · doi:10.48550/arxiv.1501.05460
28 pages, 7 figures
openalex publication_date 2015/01/22 · arxiv created 2015/07/23 · arxiv updated 2015/07/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We develop a new method of representation of quantum states in terms of the displaced number states. We call it representation, where is an amplitude of the base displaced states. In particular, representation was obtained for set of the displaced number states with different amplitude of the displacement, two-mode squeezed vacuum (TMSV) and superposition of vacuum and single photon. The treatment is employed for building of elementary linear operators, in particular, two-qubit control-sign gate, Hadamard matrix between two two-dimensional Hilbert spaces. Main idea underlying the method is extraction of the displaced number state from initial state. Coherent qubit with large amplitude taken simultaneously two modes shifts two-mode target qubit on phase plane and constructive interference appears after measurement of single photon. The results are exact, any approximations are not exploited. We show implementation of the gates with almost unity fidelity of the output states is possible in realistic scenario.