Quantum Information Processing

, Volume 13, Issue 8, pp 1723–1749 | Cite as

Elementary quantum gates with Gaussian states



We study the question of converting initially Gaussian states into non-Gaussian ones by two- and three-photon subtraction to improve non-classical properties of the conditional optical fields. We show the photon subtraction may effectively generate non-Gaussian states only in case of small values of the mean values of the position and momentum operators. In particular, the photon-subtracted state can be made arbitrary close to Gaussian state in limiting case of large initial amplitude of displacement. Use of initial displacement in input Gaussian states opens wider prospects to manipulate them. In particular, realization of probabilistic Hadamard gate with input Gaussian states is discussed where photon subtraction is motive force able unevenly to increase measure of non-classicality of the output state. Subtraction of larger number of photons enables to increase fidelity and non-classical measure of the conditional states.


Gaussian states Non-Gaussian states Measure of non-locality 



In this work, S. Podoshvedov is supported by Brain Pool Program of Korea under project number 122S-1-3-0468. K. Kim has been supported by Basic Science Research Program through National Research Foundation of Korea under contract number 2010-0007724 and also by Inha University. The work of S.A.P. was (also) supported by program of reproduction of personnel of Southern Ural State University.


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Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  • Sergey A. Podoshvedov
    • 1
    • 2
    • 3
  • Jaewan Kim
    • 2
  • Kisik Kim
    • 2
    • 3
  1. 1.Department of General and Theoretical PhysicsSouth Ural State UniversityChelyabinskRussia
  2. 2.School of Computational ScienceKorea Institute for Advanced StudySeoulSouth Korea
  3. 3.Department of PhysicsInha UniversityIncheonSouth Korea

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